Spring, 21XX. Radical feminist movements have remade Japan into a society run entirely by women. Under the Gender Segregation Act passed decades prior, boys are removed from their families at birth and placed in concentration camps where they are raised as soldiers. The world has achieved the kind of utopia some always claimed to want. One boy escaped this system. Originally a child soldier, he constructed a false identity and settled into a quiet life in a remote village with an adoptive mother and sister — until a social management AI called Mother issues a directive: he must attend the Security Force's training academy for women. He does, disguised, and is assigned to a dormitory where he meets Akari, a genuinely kind girl, and develops real feelings for her while concealing the one fact that could destroy everything. In this society, even people who seem kind hold the expectation that men should be eliminated entirely.