Sumireko Usami is the final boss of Urban Legend in Limbo, a playable character in Antinomy of Common Flowers, as well as the main protagonist of Violet Detector. She's a human from the Outside World with psychic powers (ESP). She started the Secret Sealing Club, which was taken over by Renko Usami and Maribel Hearn in the far-off future. She initially considers herself above her peers and can't stand being near those she considers beneath her, but after her defeat she gains a sense of respect for the people of Gensokyo and decides to pursue friendship with them.
(Source: [Touhou Wiki](https://en.touhouwiki.net/wiki/Sumireko_Usami))
