is the busty leader of the group and was the one who hired Jo and Meg to become members of it alongside Kyohei. She wears a long blue jacket, and has her black hair in a bun, but appears older than her stated age. Her grandfather runs Bai Lan and comes from a very powerful Chinese family. Born and raised as a traditional Chinese girl and trained in various ways of her clan/syndicate. After her grandfather stepped down as leader of the clan, their current clan members made a partnership with RAPT to preserve their clan. However such actions not only disgusted Sei, but she was forced to do many things for RAPT in Bai-Lan's name. She eventually rebelled against her own organization under the advice of her own grandfather. She was advised to walk her own path and so she chose to oppose RAPT and towards the end she was shot multiple times by a cyberoid. It is unknown if Sei survived the explosion or not.