Horizon Ariadust

Horizon Ariadust was a member of the Matsudaira family and the childhood friend of Toori Aoi. She was killed in an accident in the year 1638 TE, and a marker has been erected in Remorse Way, commemorating her death. Her death is considered to be among the most influential events in Musashi, and is known by many people inside and outside Musashi.

Ten years later, rumors circulate that Horizon lives in the body of an automaton named P-01s.