SENO MIYAGI SPOILER!

Seno Miyagi is a senior scientist on Second Earth and one of the first officials to question how the High Council is using the Sleepers. He recognizes that Marlene's presence stabilizes Yuji and argues that the two should remain together rather than treating Yuji as a laboratory asset separated from every human connection. His research into the Sleepers and their B-cells gradually exposes how dangerous the program has become. Seno's opposition to the High Council grows into the underground Ark movement, which eventually overthrows the existing leadership of Second Earth. Taking power does not give him an easy solution. His later decision to abandon Earth provokes a revolt among people who want to return, and he is ultimately killed by the population he briefly leads.