Nagaya Voyager

Spoiler Warning: Spoilers for RobiHachi may follow.

The Nagaya Voyager in flight.

The Nagaya Voyager is a spaceship that belongs to Robby Yarge, who took it with him when he ran away from home. The spaceship was then landed on top of a building in construction and became a part of it as he turned it into his apartment. Its inside, apart from areas expected in a spaceship such as a piloting cockpit, appears to be well-enough adapted to provide living conditions. It has a bedroom, a bathroom, a kitchen, and a living area, as well as at least one known storage room (that was later turned into a makeshift bedroom for Hatchi). It's possible there are even more rooms inside it: even after over a decade Robby still didn't know all of them, as he was legitimately surprised to discover Hizakuriger hidden in one airlock.
Nagaya Voyager, despite being a rather old ship, is capable of traveling at warp speed and can, overall, travel long distances, even if in general slower than newer spaceships. It was built on Yokkamarché by Armeni, who later traded it for Galaxy Traveler Hizakuriger materials with Rouche Yarge, but the latter used it mainly as a storage.
Nagaya Voyager is likely named after a nagaya (長屋, "longhouse"), a type of housing typical in the Edo period, especially considering that Robby turned his spaceship into an apartment. This reference is extended, as the housing was also referred to as yakeya (焼け家, "burning houses") and the Nagaya Voyager has caught fire.