Guardian Beast

A multilingual reading app by a published author with a Ph.D. in Engineering Developed by Takahiro Yonemura, Ph.D. (Engineering)

v2.0: Make language learning an adventure!

Let a dragon adventure spark your curiosity about language. Compare the Japanese original with a translation on the same screen, click a speaker to hear a line or choice, and revisit a favorite scene whenever you like. Explore words in the context of the story and its characters' feelings, at your own pace.

Built-in speech for Japanese, English, German and Chinese. Click the speaker beside a passage or choice to hear it in a female voice, with no extra voice packs or OS speech setup. Keep using the game while audio is generated, and stop whenever you like. Audio is generated locally on your CPU, then played when ready. Generation time depends on text length and your PC. No dedicated GPU is needed; speech requires an AVX2-capable CPU.

An interactive digital novel you can read in five languages

Read a complete 11-chapter SF-fantasy with illustrations, music, video and choices. Switch between Japanese, English, German, Simplified Chinese and Traditional Chinese, or read the Japanese original and a translation side by side. No extra font installation or change to your Windows language settings is required.

Choices appear as you read, and some actions can lead to a game over.

Travel with a dragon big sister!?

Partners in battle, yet worlds apart at heart. A crisis will test their bond.

On the verge of expulsion, young Reis summons Andromeda, a proud, copper-red dragon. At last he has a partner—but their first journey brings them into conflict with Guardians who terrorize towns and kingdoms.

Having a mighty dragon at his side does not mean they understand each other. Differences between species, feelings for their companions, and misunderstandings strain their growing bond. As the conflict becomes a threat to their entire world, can Reis and his companions bridge the divide between humans and intelligent beasts—and learn to entrust their lives to one another?

Five reading languages, regardless of your Windows language

Choose Japanese, English, German, Simplified Chinese or Traditional Chinese inside the app, even on English or Japanese Windows. Japanese and Chinese fonts are bundled with the app: no additional font installation or change to your OS language settings is required.

Read Japanese and its translation side by side

Switch between Japanese only, translation only and a paired display while reading. Compare the same passage in Japanese and English, German or Chinese, exploring language and expressions through the story. All eleven chapters are included, and switching languages preserves your reading position.

One way to read with a translation Follow the story in English → read the Japanese original → compare expressions in the paired display. This 10-second clip compares the three reading modes, then shows the bilingual choices for choosing your way into the story.

A story by Takahiro Yonemura, author of 70 books

The original author, Takahiro Yonemura (米村貴裕), has written 70 books spanning SF and fantasy fiction and IT subjects, and holds a Ph.D. in Engineering. His books have been featured in a library display, and his writing and publishing work has been covered by the press. For this Steam edition, he personally revised the original story.

A library display featuring books by Takahiro Yonemura.

A commercially published Japanese SF-fantasy novel, rebuilt as an interactive bilingual reading experience

Guardian Beast is a reading-first interactive edition of the Japanese SF-fantasy novel commercially published in 2015. In 2026, author Takahiro Yonemura extensively revised and reconstructed his original work with full-story illustrations, manga-style scene direction, sound, animation, and meaningful choices.

Bilingual Reading Mode

Read the original Japanese text alongside the English, German, Simplified Chinese, or Traditional Chinese localization. Choose Japanese only, English only, German only, Simplified Chinese only, Traditional Chinese only, or a paired bilingual display. Switch at any time and compare the original with its translation as you read.

From a bookstore novel to an interactive digital book

The story began as the Japanese book Guardian Beast, commercially published and distributed in 2015—years before today's generative-AI boom. The physical edition reached bookstore shelves and was promoted at author signing events.

For the Steam edition, Yonemura substantially revised the published manuscript. The novel's flow remains central, while light branching, music, video, and scene direction deepen the reading experience. This is interactive reading software built for enjoying a story, rather than a large-scale adventure game.

Author Takahiro Yonemura signing copies of Guardian Beast at a bookstore event (2015–2016).

What this Steam edition includes

All 11 chapters in Japanese, English, German, Simplified Chinese, and Traditional Chinese

Bilingual Reading Mode showing the Japanese original beside a translation

Full-story illustrations with manga-style panning and horizontal scrolling

Selected animated scenes, music, sound effects, and ambient audio

Name customization, choices, and autosave

The original 2015 afterword plus a new 2026 afterword

A boy, a dragon, and the bond between people and their Guardian Beasts. As war and an approaching catastrophe close in, the story moves from quiet encounters to fierce battles, heavy loss, and a final spark of humor.

Sample pages from the original 2015 book manuscript.

About the artwork

Some illustrations and visual materials in this edition were created with generative AI and then selected, edited, and integrated by the development team.