International Ruby Programming Contest for Junior and Senior High School Students 2023 in Mitaka The Final

公開日 2024年02月20日


Report of the Final Competition

Group photo

The “International Ruby Programming Contest for Junior and Senior High School Students in Mitaka” aims to foster younger people’s passion and dreams for the future through learning programming, experiencing the excitement of operating a computer by themselves, and presenting the work they have created. 

The final stage of the 13th International Ruby Programming Contest was held at Mitaka Industrial Plaza on Saturday, December 9, 2023.

Out of a total of 124 competition entries, 6 works in the game category and 5 in the web application/IoT category were selected for the finals.

Opening Ceremony

The contest began with an opening speech by Inoue Hiroshi, CEO of OSS-Vision Co., Ltd., and chairman of the executive committee of the International Ruby Programming Contest for Junior and Senior High School Students.
Mr. Inoue praised the charm of programming and the efforts of the applicants, saying, “Everyone, please be proud of having made it to the final round and enjoy the contest. Don't be nervous and enjoy presenting.”  He also expressed his gratitude to the staff and sponsors who supported the tournament.

Inoue Hiroshi, Executive Committee Chairman
▲Inoue Hiroshi, Executive Committee Chairman


Following the opening remarks, messages from three Ministries (Ministry of Economy, Trade and Industry; the Ministry of Internal Affairs and Communications; and the Ministry of Education, Culture, Sports, Science and Technology) were read, mentioning the importance of programming technology and young peoples’ role as the main player to lead the digital transformation of society.

Next, the judges were introduced: 
Mr. Matsumoto Yukihiro (Matz), creator of Ruby and chairman of the judging committee (Chairperson of the Ruby Association)
Mr. Noda Tetsuo (Professor, Department of Law and Economics, Faculty of Law and Literature, Shimane University)
Mr. Tanaka Kazuaki (Associate Professor, Graduate School of Computer Science and Systems Engineering, Kyushu Institute of Technology) 
Mr. Sasada Koichi (Full-time Ruby Committer, STORES Inc.)
Mr. Takahashi Masayoshi (Representative Director, Japan Ruby Association)
Mr. Mori Masaya (Executive Officer/Partner, Deloitte Tohmatsu Consulting LLC) 
Ms. Emori Mayumi (Executive Officer, KCS Carrot Corp.) 
Each judge gave a message of encouragement.

Also, messages were given from the companies which provide sponsor awards: SonicGarden Inc., Eiwa System Management Inc., and pixiv Inc.
Each company gave cheering messages.
Finally, the presenters were introduced. Each presenter from the game division and web application/IoT division showed enthusiasm by making a pose.


Guts pose  Guts pose  Guts pose


Presentation by the Contestants

― Game Division 

Grand Prize
Team “Diceman”(Iwate Prefecture)
Science and Technology Club
Takizawa Second Junior High School, Takizawa City, Iwate Prefecture 
Title: “DICE”

Iwate Prefecture  Title: “DICE”  Takizawa Second Junior High School, Takizawa City, Iwate Prefecture   

"DICE", presented by Matsukusa Kai (in charge of programming) and Sakashita Wataru (in charge of graphics) won the grand prize in the game category. In this number matching puzzle game, players move rows of dice to clear them. The game features strategic elements that aim for high scores by forming combos. Rankings are made based on the points earned when the game is cleared. Using high-school mathematics, the program incorporates three-dimensional display and hidden surface processing with normal vectors. During the demonstration operation, "DICE Master WATARU" performed an impressive play, and the presentation was full of humor.

Matsumoto Yukihiro, Chairman of the judging committee, praised the use of high school mathematics learning, saying, “In recent trend that people generally doubt the practicality of mathematics, they specifically demonstrated its usefulness.''  Matsumoto praised the high degree of completion as a puzzle game, as “a level comparable to that of professionals.”

The members of the team “Diceman” said, “Last year we won the Special Jury Award, but this year we were able to get our revenge and are happy to have won the top prize.” They expressed their gratitude to his teachers, instructors, club members, and families.

Excellence Award
Nohara Hiroto (Ehime Prefecture)
Ehime Prefectural Matsuyama Technical High School
Title: "Stealth Game"

Nohara Hiroto (Ehime Prefecture)   Title: "Stealth Game"  Ehime Prefectural Matsuyama Technical High School   

The Excellence Award went to “Stealth Game” which is a game where the objective is to proceed without being detected by the enemy. “The goal and appearance are simple, because I designed it so that many users can enjoy it,'' says Nohara. Each stage has a high degree of freedom, allowing players to find a variety of strategies, including finding safe routes and routes that take less time. A demo of the game introduced level selection, player and enemy movement, and the characteristics of each stage. Nohara put a lot of thought into the game's strategy routes, time attack function, and stage changes.

Judge Mori Masaya praised "Stealth Game", saying, “It was a very well-crafted and entertaining game.” He also explained that the fact that Nohara was able to set multiple strategy routes and thoughtfully devised the program was a proof that ‘he had made this game his own’.  Judge Mori also said that he could feel Nohara’s love for games in his hand-drawn pixel art. He highly praised Nohara's passion and talent for game creation and concluded that he has high hopes for Nohara's future work.

Regarding receiving the Excellence Award, Nohara said, “I feel happy and disappointed at the same time,” expressing his desire to further grow and take on challenges.

Special Jury Award/Matz Award
Team “Rumored Seafood Senpai” (Iwate Prefecture)
Science and Technology Club 
Iwate Prefecture Takizawa City Takizawa Second Junior High School
Title: “Challenging Spy”

Team “Rumored Seafood Senpai” (Iwate Prefecture)  Title: “Challenging Spy”  Science and Technology Club     

“Challenging Spy,” which won both the Special Jury Award and the Matz Award, is a work presented by “The Rumored Seafood Senpai” team. The game depicts the story of a rookie spy who steals confidential information from a large company. Programmer Endo Honoka said, “We focused on the sound and graphics to express the tension and fear of being a spy,” and Yanagimura Yu, in charge of graphics, said, “This was my first attempt at animation, and I aimed to create a production that would enhance the sense of immersion into the game.” As future improvements, they are considering extending time limits and randomizing item placement.

Judge Sasada Koichi said, “The presentation was excellent, and the question and answer session was very powerful,” and he praised their teamwork through division of labor, saying it was “like a professional game development team.”

The two third-year junior high school students said, “When I look back on my three years of extracurricular activities, programming was fun. It was a valuable experience to interact with so many people,” Endo said, while Yanagimura said,  “I am thrilled to have won two awards. There were times when we had different opinions, but I am very happy now.” This contest is not only a competition of skills, but also a place for growth and discovery.

Special Jury Award 
Miyata Soushi (Ehime Prefecture)
Ehime Prefectural Matsuyama Technical High School 
Title: “3D Maze”

Miyata Soushi (Ehime Prefecture)  Title: “3D Maze”  Ehime Prefectural Matsuyama Technical High School   

Miyata Soushi’s “3D Maze'', which won the Special Jury Prize, is a game where you can explore the maze from a first-person perspective and defeat enemies to collect items to advance through the floors. Miyata said, “I pursued realism by taking advantage of perspective in visuals. Also, by using a limited perspective, I created a sense of tension and fear.” Looking to the future, he says, “To avoid being monotonous, I am considering adding bosses, setting small goals and achievements, and even introducing RPG elements, aiming to deepen the gameplay.''

Judge Takahashi Masayoshi praised “3D Maze” saying, “The basic structure is solid. I was impressed by the refined details such as the movement of the 3D graphics and the automatic generation of the map.”  Judge Takahashi suggested adding stages and bosses for future development, and said he hoped that the game would become even more appealing.

Receiving the award, Miyata expressed his gratitude, saying, “I was truly surprised to receive the award. Being here is itself a great honor for me. I sincerely thank everyone for their support.''

Special Jury Award 
Hino Yosuke (Ehime Prefecture)
Ehime Prefectural Matsuyama Technical High School 
Title: “Craft Roguelike”

Hino Yosuke (Ehime Prefecture)  Title: “Craft Roguelike”  Ehime Prefectural Matsuyama Technical High School  

Hino Yosuke’s “Craft Roguelike” won the Special Jury Award. This is a game where you aim to survive as long as possible by making full use of survival strategies. In this game, players start out without any weapons and then improve their armaments and status by defeating enemies. In his demo play, Hino introduced stage selection, difficulty settings, and automatic map generation functions. Players are supposed to collect materials such as wood and stones to craft weapons, and fight against enemies. Hino explained the main point of his device, saying, “I made it so that Each stage has its unique gimmicks and items and provide different levels of difficulty and experiences.” He is also tackling technical challenges, such as improving operability and fine-tuning hit detection.

Judge Noda Tetsuo called it a “highly addictive and attractive game.” He pointed out the expandability of the game’s tool making and the way of fighting with enemies and expressed his hopes for the future.

Regarding the award, Hino expressed his honest feeling, saying, “I'm happy to have won the award.”

Special Jury Award
Akiyama Sotaro (Ehime Prefecture)
Ehime Prefectural Matsuyama Technical High School
Title: “ten days”

Akiyama Sotaro (Ehime Prefecture)  Title: “ten days”  Ehime Prefectural Matsuyama Technical High School  

The Special Jury Prize went to “ten days'' by Akiyama Sotaro. It is a survival game where the objective is to survive for 10 minutes by managing the durability of tents and bonfires. The game has five stages that change every minute, which is unique, and players collect items and complete tasks to maintain their durability. “I had a hard time implementing the left-handed/right-handed control settings and the ranking system,” says Akiyama. Possible future improvements include adding new stages and tasks and changing play time.

Judge Tanaka Kazuaki said, “It's a simple game where the story progresses on a single screen without scrolling, but it's an extremely complete game that shines with ideas and careful craftsmanship, such as the special effects of each stage.''  Tanaka also praised Akiyama’s attention to left-handed user interface.

Upon receiving the award, Akiyama expressed his joy by saying, “I am very happy that the left-handed setting has been praised. I am grateful for this award.''

Web Application / IoT Category

Grand Prize/Eiwa Prize
Kanemitsu Shunki (Mie Prefecture)
Title: “SQSO Web”

Kanemitsu Shunki (Mie Prefecture)  Title: “SQSO Web”  Kanemitsu Shunki (Mie Prefecture)  

The winner of the Grand Prize in the Web Application/IoT category and the Eiwa Award was “SQSO Web” by Kanemitsu Shunki, which is an electronic log management application for amateur radio. Mr. Kanemitsu said, “Amateur radio and train travel are my hobbies,” and his motivation for developing the app was “because there was no logging software available for my club activities,” and explained the appeal of amateur radio and the importance of logging. His work "SQSO Web" is rich in originality, such as the use of RODA and the implementation of database migration using Rake tasks.

Matsumoto Yukihiro, Chairman of the judging panel, praised Kanemitsu's work, saying, “While dealing with very niche amateur radio call logs, his enthusiasm and ability to create what he needed was outstanding.” “Including the technical choices, it was very innovative,” he said. Matsumoto announced that Kanemitsu was unanimously selected for the Grand Prize.

Upon receiving the award, Kanemitsu humbly commented, “I haven't really felt the reality of winning the top prize yet,” and “I would like to thank my family, programming teacher, and club friends.” And to other web application developers, he said, "I recommend using RODA."


 Excellence Award/pixiv Award
Koizumi Mana (Tokyo)
Title: “Summin-up”

Koizumi Mana (Tokyo)  Title: “Summin-up”  Koizumi Mana (Tokyo)  

The winner of the Excellence Award and the pixiv Award was Koizumi Mana’s English learning app "Summin-up."  Koizumi, a returnee student, felt that her high school had no English classes for returnee students, and opportunities for output had decreased, so she searched for a learning method for intermediate English learners and above, but could not find anything suitable. In order to solve this problem, she developed "Summin-up" by herself. This app is an SNS with English summaries. It is designed to help users learn English naturally based on their interests.

Judge Mori Masaya highly praised Koizumi's approach, saying, “It is impressive that Koizumi developed a service that utilizes the latest technology such as ChatGPT in response to the clear theme of maintaining the English proficiency of returnee children.”

Koizumi showed both humbleness and appositive attitude, saying, “I am very honored to have received two awards. I am grateful to have been able to give the presentation and to have been inspired by the other participants. I would like to continue developing the product in the future.'' 


Special Jury Award/SonicGarden Award/Matz Award
Inoue Rentaro (Osaka Prefecture)
Title: “AniSphere”

Inoue Rentaro (Osaka Prefecture)  Title: “AniSphere”  Inoue Rentaro (Osaka Prefecture)  

The anime sharing app "AniSphere" developed by Inoue Rentaro won three awards: the Special Jury Award, the SonicGarden Award, and the Matz Award. Inoue, an anime lover, felt that there was a lack of a place where people could freely discuss anime, so he developed “AniSphere.” This app provides a review function for anime fans and a unique tweet function that allows free posting. You can hide content that contains spoilers, and you can also post information that is difficult to share on SNS. In the demonstration, Inoue introduced how to register for an account, review, and use the tweet function. On the technical side, he achieved efficient development by using Ruby on Rails in API mode and switching to Next.js for the front end. He has made many improvements, including faster rendering, improved UI, and ease of mobile app development. Inoue has also added a direct message function with a stamp function and unsend function, and a spoiler group function to encourage interaction between users. Improvements to the API include optimizing the table design for the comment function, strengthening security, and implementing two-factor authentication. Inoue said, “Increasing the number of users is currently my biggest challenge. I am also considering the introduction of real-time communication using Web socket communication and its future developments.”

Judge Noda Tetsuo said, “AniSphere is a wonderful service for anime fans,” and advised that “increasing the number of users is important,” adding, “The challenges that come with increasing the number of users are also attractive for development.”

Inoue expressed his gratitude, saying, “I am very happy to have won so many awards. Thank you very much.” He also said, “I'm grateful that Ruby was the first programming language I understood, and that it inspired me to create the service I love.”  Inoue expressed his joy of being chosen by Matsumoto Yukihiro and his regret that he could not meet Matsumoto in person.


Special Jury Award
Kuchida Michiya (Okayama Prefecture)
Title: “Local Production for Local Consumption Project”

Kuchida Michiya (Okayama Prefecture)  Title: “Local Production for Local Consumption Project”  Kuchida Michiya (Okayama Prefecture)  

Kuchida Michiya’s "Local Production for Local Consumption Project" won the Special Jury Award. This app is a system that promotes locally produced products to be consumed locally. Kuchida explained the issues the project is addressing, citing his friends who cannot afford expensive fishing gear, the problem of irregular vegetables that cannot be sold on the market, and his experience at an after-school day service called “Hoharu.” He aimed to develop a platform that would facilitate the sale of local products and strengthen local communities. In his demonstration he emphasized the ease of transaction by introducing the process from product listing to transaction, allowing the users to choose their own transportation method. On the technical side, Kuchida adopted Ruby on Rails and PostgreSQL, with an emphasis on security and responsive design. For future improvements, he mentioned the introduction of asynchronous communication and more efficient post management.

Judge Emori Mayumi said, “The approach of solving a friend's problem through programming and based on local production and local consumption activities in the region is wonderful.”  She also said that responsive design is easy for anyone to use and suggested adding a map feature in the future.

Kuchida expressed his excitement, saying, “It's difficult to express in words the joy of receiving the award. I'm happy that I won the award in my first contest.'' He added, “I want to aim for the top prize next time,” with even more enthusiasm. 


Special Jury Award
Ishizaki Ryu (Tokyo)
Title: “AI Diagram”

Ishizaki Ryu (Tokyo)  Title: “AI Diagram”  Ishizaki Ryu (Tokyo)  

"AI Diagram" developed by Ishizaki Ryu won the Special Jury Award. This app was designed to help you generate ideas. Ishizaki said, “As I myself found it difficult to create mind maps, I developed "AI Diagram" based on the research results that many people have trouble coming up with ideas and to solve the difficulties of traditional mind maps.” In this app, when a user sets a theme, AI generates related terms and builds a mind map. In his demonstration, Ishizaki used the theme of "grape picking" and introduced the save function and the function to restart associations from past maps. On the technical side, he explained how to create a mind map using the Highcharts library using the ChatGPT API.  Ishizaki expressed his desire to work on further improvements to the app, such as analyzing responses and improving the UI by using regular expressions and optimizing response speed.

Jury member Takahashi Masayoshi said, “ ‘AI Diagram’ is an app that skillfully combines idea generation and means of realizing it, and you can use it immediately.” He advised, “I hope he will dig deeper into existing functions and develop tools from new perspectives.”

Upon receiving the award, Ishizaki said, “It was a very happy experience for me to participate in this contest at the end of my high school days. I am truly grateful.'' He looked back on his progress so far and expressed his expectations for a new start.


【Comment and Special Lecture】

Matsumoto Yukihiro, Chief Jury 

Matsumoto Yukihiro, Chief Jury


This year's "International Ruby Programming Contest for Junior and Senior High School Students" was of a particularly high level, and all the judges were impressed by the quality.

In the game category, we found many surprising works. Miyata Soushi's “3D Maze” was a modern arrangement of nostalgic elements. Akiyama Sotaro's “ten days'' expresses a variety of elements on a single screen. The “Challenging Spy” by the team "Rumored Seafood Senpai" shined with its carefully thought-out design. “DICE” by Team “Diceman” was a puzzle that makes full use of mathematics, and Nohara Hiroto's “Stealth Game” was impressive with its ingenious screen design. Hino Yosuke's "Craft Roguelike" stands out for its new approach to collecting materials.

In the web application/IoT category, Kuchida Michiya's "Local Production for Local Consumption Project" demonstrated high level of his social awareness. Inoue Rentaro's “AniSphere” was a work full of enthusiasm and generous support.  Koizumi Mana’s “Summin-up'' was an excellent app showing her awareness of issues from her experience as a returnee. Ishizaki Ryu's "AI Diagram" was full of modern charm. Kanemitsu Shunki's "SQSO Web" received high praise from all the judges for its technical originality and enthusiasm.

Each winner of the 2023 contest can be proud of their achievements.

【Special Lecture】
Theme: “The Power of Programming”

In the special lecture of "International Ruby Programming Contest for Junior and Senior High School Students 2023 in Mitaka", I will talk about "the power of programming".

The first computers I used in middle school had limited resources, but today we have access to powerful computers, and the evolution of the Internet has made it easier to access new information and tools. .

The real thrill of programming lies in the freedom to create something on your own. Instead of relying on someone else's work, you can create what you want by yourself. There are almost no restrictions in adjusting the difficulty level, changing the rules, freedom of design, and so on.

Creating your own world is a unique process, just like that of other creators such as novelists and film directors. Programmers can also create their own worlds. Programming is important not only for entertainment but also as a means of problem solving.

Designing programming language expands your options and increases your freedom. It was my love for programming and my desire to "decide and think for myself" that became drove me to create Ruby. 

I've always been fascinated by the creativity of programming and its power to create new worlds. From game world building to problem solving, the possibilities are endless.

Now it’s time when we have lower barriers to learning and have more opportunities offered.  I'm sure your skills and passion will continue to produce wonderful creations.

Finally, programming is more than just a technology; it's an important tool for shaping your world. It will play an even more important role in the future. We look forward to seeing your carving out your own future.

Closing Ceremony

Mr. Yoshida Sumio, deputy executive committee chairman

At the closing ceremony of the 2023 International Ruby Programming Contest for Junior and Senior High School Students, Mr. Yoshida Sumio, deputy executive committee chairman and representative director of Mitaka Town Management Inc., congratulated all the award winners and praised the high level of their works. He expressed his relief that the event could be held face-to-face for the first time in a long time after overcoming the impact of the new coronavirus, and concluded by expressing his gratitude to the sponsors, judges, and executive committee members.