In the spring of Kyoko's freshman year of high school, her pseudo-sibling Eiko returned with her younger brother Jiro. While their homecoming was unremarkable, Jiro had a shocking plan to perform surgery on Kyoko. To complicate matters, both siblings were members of a group that aimed to disrupt global peacefulness. As if high school wasn't already challenging enough, Kyoko now had to navigate living with these two individuals.