OVA
Description
Kō Satomi is a character who appears as a supporting antagonist in the OVA Lostorage conflated WIXOSS -missing link-, which serves as a bridge between the first and second television seasons of the Lostorage arc. He originates from the earlier series Lostorage incited WIXOSS, where he serves as the primary antagonist. Within the world of the Selector battles, he is known among participants by the moniker Bookmaker, a reference to his function of arranging and facilitating matches for Selectors who are unable to find opponents on their own. His background is that of an adult male with black hair and blue eyes, and his activities in the series place him in a position of manipulation behind the scenes of the conflict.

His personality is characterized by a calculating and nefarious nature. He operates with a cold, instrumental view of the Selector system, treating the battles and the participants as pieces in a larger scheme. His motivations are rooted in control and the perpetuation of the battle system itself; rather than seeking a personal wish through victory, he seems driven by the desire to orchestrate the outcomes and extend the cycle of conflict for his own purposes, which may include observation, experimentation, or the exercise of authority over the Selector ecosystem.

In the narrative of the Lostorage series, Satomi plays the role of a hidden puppeteer who influences the course of the battles from the shadows. In Lostorage incited WIXOSS, his actions drive much of the conflict, as he actively intervenes to shape which Selectors face each other. By the time of Missing Link, he has been defeated by the protagonists Suzuko Homura and Chinatsu Morikawa in a grueling battle, allowing the two girls to return to a semblance of normal life. However, his defeat does not bring an end to his influence; even after his fall, his plans continue to manifest, with supporters attempting to resurrect his schemes. This lingering impact compels Kiyoi Mizushima to seek help in investigating the renewed Selector activity, and Satomi's legacy remains a central concern as new threats emerge.

His key relationships are defined by his role as an antagonist. He opposes Suzuko Homura and Chinatsu Morikawa, who ultimately defeat him. He also stands in opposition to Kiyoi Mizushima, who becomes aware that his influence has not been fully extinguished. His relationship with other Selectors is transactional and exploitative; he does not form alliances based on trust but rather uses them as assets in his designs.

Regarding development, Satomi does not undergo a redemption arc or significant personal change within the timeframe of Missing Link. He remains a defeated but persistent threat whose actions continue to resonate. His defeat marks the end of his direct involvement, but the narrative emphasizes that his machinations have set events in motion that outlast his personal presence.

As for notable abilities, Satomi does not possess supernatural powers of his own; his strength lies in his knowledge of the Selector system and his ability to manipulate it from the outside. He is not a direct combatant in the battles themselves but rather a coordinator and schemer. His skill in matchmaking and information gathering allows him to exert influence over the course of the conflict, making him a formidable opponent despite his lack of personal engagement in the card game.