Masahiro lost his mother and lives with his father. - Masahiro is living the life of a NEET, unable to balance work and childcare with only his father and arm. - At that time, Anna, whose father remarried and became her stepmother, arrives. - Anna, who was shocked to see the dilapidated house of a single-parent family, begins by cleaning Masahiro's room in order to improve his life. - However, Masahiro, who has come into his territory and is so repulsed by her, plots to harass her in order to push her away...