About the Project
Hoshi no Isan 星の遺産 — Children of the JAXA Legacy
Why Hoshi no Isan
Japan's space program produced some of the most remarkable engineering stories ever told. Spacecraft that refused to fail. Missions that waited years for a second chance. Almost none of these stories have been told in gaming.
Hoshi no Isan puts you aboard the Yamabiko — a JAXA Heritage Ship crewed by the children and grandchildren of Japan's greatest space pioneers. You are their commanding officer. Lead them. Know them. Earn their trust.
The game combines first-person exploration of the ship, visual-novel dialogue with crew members, a gacha-style recruitment system grounded in real JAXA history, and a crew wellbeing system. No combat, no resource grinding — the focus is on relationships, discovery, and the stories embedded in every corridor. The full design is documented in our Game Design Document, and development progress is shared in the Dev Journal.
Three pillars define the experience: exploration (walk the Yamabiko in first person, read lore, find secrets), relationships (earn trust with crew through dialogue and choices), and legacy (every character and room ties back to a real mission — Hayabusa, Kaguya, SLIM, Akatsuki, and more). The ship and crew pages go into detail; the Legacy Archive holds older project posts from 2010 onward.
"The ship is not just where the story happens. The ship is the story. Every compartment is a shrine. Every crew member is a descendant."
Solo Indie · Unreal Engine 5
One Developer, One Vision
Hoshi no Isan is being built by a solo developer with deep roots in Japanese culture and a lifelong love of space. Every line of code, every design decision, every breakthrough — and every setback — is documented in the Dev Journal.
Why JAXA
JAXA's legacy deserves an audience beyond the mission teams. Hayabusa, Hayabusa 2, Kaguya, Akatsuki, SLIM — these missions tell stories of perseverance that belong in games. We're making sure they get there.
The JAXA Missions page summarizes each mission that inspired the ship and crew. If you want to dig into the design — deck flow, trust system, recruitment — the GDD is the place. The Developer page introduces the solo dev behind the project.
Explore the Game
Walk the ship. Meet the crew. Read the design.
Hoshi no Isan Game Design Document Dev Journal