After thirty days of endless affection, even a mother's reason must break.

After his friend Himori comments on how beautiful his mother is, Takuro begins to see her in a new light. His feelings intensify as he catches glimpses of her in unguarded moments around the house. With his father away on a long-term business trip, Takuro decides to confess his romantic feelings. Though initially dismissed, he refuses to give up and spends the next month showering her with affection every single day. The tension reaches a breaking point when his mother discovers his secret obsession, leading to a collapse of her maternal restraint and the start of a repetitive, forbidden physical relationship.