Explore the Yamabiko
ほしのいさんA Japanese-aesthetic space visual novel and crew RPG set aboard the JAXA Heritage Ship — a living museum of Japan's most legendary space missions. Explore every corridor. Know your crew. Carry the legacy.
In Development — Solo IndieA Ship With Memory
Japan's space program produced some of the most extraordinary engineering stories ever told — spacecraft that refused to fail, missions that waited years for a second chance, rovers that landed upside down and still completed their objectives. Almost none of these stories have been told in gaming. Hoshi no Isan changes that.
"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."
You are the new commanding officer of the Yamabiko — a JAXA Heritage Ship crewed by the children and grandchildren of Japan's most celebrated space pioneers. Each deck is named after a mission. Each crew member carries their ancestor's philosophy, personality, and unresolved legacy. Your role is to lead them into a fantastical space frontier while honoring the history written into the ship's walls.
This is not a combat game. It is a game about care — for your crew, for the stories they carry, and for the vast, beautiful unknown ahead of you.
The Missions That Built This Ship
Each section of the Yamabiko is dedicated to a legendary JAXA mission. These are real stories. Real perseverance. The ship remembers them so your crew never forgets.
🛸 Hayabusa — The One That Refused to Die
Engine failures. A seven-year communication blackout. Fuel leaks that should have ended everything. The original Hayabusa probe limped home across two billion kilometers on a single functioning engine and delivered asteroid samples in 2010. Japan wept when it re-entered atmosphere. The engineering team had never given up.
This mission defines the ship's core philosophy: ganbaru — persevere regardless.
ASTEROID ITOKAWA SAMPLE RETURN Hayabusa Engine Bay — B Deck🌑 Hayabusa 2 — The Perfectionist
Hayabusa 2 did everything its predecessor could not — and then kept going. It deployed multiple rovers onto asteroid Ryugu, fired a copper bullet into the surface, collected subsurface samples, and returned them to Earth in 2020. Rather than retiring, the spacecraft continued on to a second asteroid target. A mission that refused to stop at complete.
ASTEROID RYUGU SURFACE IMPACT Hayabusa Science Lab — C Deck🌕 Kaguya (SELENE) — The Poet
The Kaguya lunar orbiter produced the first HD video footage of Earth rising over the lunar surface — one of the most beautiful things ever recorded in space. Named after the legendary moon princess of Japanese folklore, the mission gave humanity a new way to see its own home. A camera pointed outward, returning something deeply interior.
LUNAR ORBIT HD IMAGING Kaguya Observation Lounge — A Deck☁️ Akatsuki — The Patient One
Akatsuki failed to enter Venus orbit in 2010 when its main engine burned out. The team did not abandon it. They waited five years, used tiny attitude thrusters never designed for orbital insertion, and successfully placed the spacecraft into Venus orbit in 2015. Five years of patience. One second chance. A mission that taught Japan — and the world — what waiting with purpose looks like.
VENUS ORBIT ATMOSPHERIC SCIENCE Akatsuki Meditation Room — D Deck🌙 SLIM — The Precise One
Japan's Smart Lander for Investigating Moon touched down in January 2024 with pinpoint accuracy — within 100 meters of its target, compared to the usual 10 kilometer error margin. Its main engine failed and it landed inverted. It still completed its primary mission objectives. The most accurate lunar landing in history, executed upside down.
LUNAR LANDING PRECISION NAVIGATION SLIM Navigation Bridge — A Deck🌍 Japanese ISS Legacy — The Bridge Builders
Koichi Wakata became the first Japanese ISS commander in 2014. Akihiko Hoshide led the first Asian spacewalk command in 2021. Soichi Noguchi flew on three missions across three decades. These astronauts did not just explore space — they built the human infrastructure that makes international space cooperation possible. Their legacy is the ship's command philosophy.
INTERNATIONAL LEADERSHIP ISS Heritage Gallery — B DeckChildren of the Pioneers
Recruit the descendants of Japan's greatest space pioneers. Each crew member carries their ancestor's philosophy, specialty, and a personal story waiting to be unlocked. These are not random characters — they are heirs to a real legacy.
Hana Mukai
First Japanese woman in space, 1994 & 1998
Precise, methodical, and quietly fierce. Inherited her grandmother's cardiovascular surgeon instincts and the unshakeable belief that a healthy crew is an unstoppable crew. Never loses her composure — but notices when you do.
Kenji Mohri
First JAXA astronaut in space, 1992
A materials scientist who sees patterns others miss. Thoughtful to the point of silence, Kenji observes before he speaks — and when he speaks, the crew listens. Inherited his grandfather's belief that the most important discoveries happen quietly.
Yuki Wakata
First Japanese ISS Commander, 2014
Born to lead but determined to earn it. Yuki carries the weight of her father's legacy with visible effort — she will not accept the title until she believes she deserves it. One of the most skilled navigators on the ship.
Ren Hoshide
First Asian spacewalk commander, 2021
At home outside the ship as inside it. Precise, fearless in the void, and deeply committed to the crew's collective mission. Has never met a technical problem he was willing to call unsolvable.
Sora Noguchi
Three missions across three decades, 1996–2021
The keeper of the ship's memory. Sora has read every mission report, every engineering log, every personal letter sent from orbit. She knows what the ship has survived. She makes sure no one forgets it.
Hayato Itokawa
Never gave up. 7 years. 2 billion kilometers.
The most stubborn engineer on the ship — and proudly so. Hayato believes any system can be coaxed back to life with enough patience. The Hayabusa engine bay is his sanctuary. He understands machines that refuse to quit.
Additional crew members will be added through exploration, story events, and honorific recruitment.
Some ancestors have never been publicly acknowledged — their descendants carry quiet legacies waiting to be discovered.
Every Corridor Tells a Story
The Yamabiko (ヤマビコ — echo of the mountain) is named for the Japanese folkloric spirit that answers back, that carries memory of what was said. Walk every deck in first person. Each compartment is named after a mission. Each wall holds something worth reading.
Kaguya Observation Lounge
The ship's most beloved space. A wide curved viewport with the HD Earth-rise footage playing on loop — the same footage that moved the world in 2007. Crew gather here when they need perspective. Visual novel scenes frequently play out here at night cycle.
Hayabusa Engine Bay
Hayato's territory. A functional engineering space with schematics of the original Hayabusa ion drives on the walls and a small shrine to the spacecraft that came home against all odds. The most emotionally charged room on the ship.
Hayabusa Science Laboratory
Kenji's workspace. Clean, methodical, and filled with sample containers from asteroid Ryugu — replicas, but treated with the same care as the originals. A science space that honors the mission that proved perfectionism is achievable.
SLIM Navigation Bridge
The command center. Precise, minimal, and slightly tilted — a design choice honoring SLIM's own inverted landing. The most accurate navigation suite on any fictional ship, because the mission it honors demanded 100-meter precision. Yuki's domain.
Akatsuki Meditation Room
A quiet room at the center of the ship with a single viewport facing aft. Named after the mission that waited five years for its second chance. This is where crew members come when they need to wait with purpose. Where the best conversations happen.
ISS Heritage Gallery
A long corridor lined with portraits, mission patches, and personal artifacts from every Japanese astronaut who served on the International Space Station. Sora maintains this space meticulously. Walking its length is a history lesson that never feels like one.
Four Pillars
FPS Ship Exploration
Walk every deck of the Yamabiko in first person. Find hidden logs, mission artifacts, and crew items. The ship reveals its stories to those who take time to look.
Visual Novel Narrative
Deep crew relationship storylines with branching dialogue. A trust system tracks every choice — unlock ancestor biographies, new rooms, and story arcs as trust deepens. What you say shapes who your crew becomes.
Crew Gacha System
Recruit descendants of real JAXA astronauts and engineers. Each crew member has a rarity tier, ancestor biography, and unique role aboard the Yamabiko. Collect, develop, and care for your team.
Crew Wellbeing
Your crew's emotional state matters as much as their technical roles. Monitor morale, resolve conflicts, and create the conditions for your team to thrive. A cared-for crew is capable of anything.
Building Honestly
This is a one-person project built with Unreal Engine 5 Blueprints, acquired assets, and a lot of conviction. The roadmap reflects what's actually achievable — starting small, finishing real things.
Unreal Engine Foundation
Learn UE5 Blueprint system. First-person character controller. Basic ship interior navigation. One room functional — the Kaguya Observation Lounge. This is the proof the concept can be built.
The Yamabiko MVP Interior
Three to five ship compartments fully explorable. Basic interaction system. Environmental storytelling through props, plaques, and mission artifacts on every wall. The ship must feel inhabited before anyone lives in it.
First Crew Member — Sora Noguchi
Visual novel dialogue system implemented. One complete crew story arc — Sora, the ship's historian. Branching dialogue, trust meter, ancestor biography unlocks. If one crew member's story works, all of them can.
Gacha Foundation & Crew Roster
Core gacha recruitment system. Full initial crew of six descendants live with partial story arcs. Crew wellbeing system tracking morale and relationships. The game begins to feel like itself.
Alpha — The First Voyage
One complete story arc from departure to destination. Full ship exploration. All six initial crew members with their ancestor stories. A game someone can play from beginning to end and feel something.
Development JournalBuilding Hoshi no Isan in Public
A solo indie dev learning Unreal Engine 5 while building a love letter to Japan's space program. Every step documented — the breakthroughs, the failures, and the very long Unreal load times.
Follow the Mission
使命を追うHoshi no Isan is being built in public by a solo developer with deep roots in Japanese culture and a lifelong love of space. JAXA's legacy deserves an audience beyond the mission teams. If that sounds like something worth watching, follow along.