Hajimete no Aku

Kyoko is a first-year high school student when Eiko, a girl she considers a sister, returns with her younger brother, Jiro. Their arrival is unexpected, and Jiro becomes fixated on performing a surgery on Kyoko. Complicating matters further, Eiko and Jiro are part of a group that seeks to undermine global peace. Now Kyoko must manage the challenges of high school while dealing with the two of them living under her roof.