Koga Tomonori is an ordinary college student and the only son of a typical middle-class family. A year and a half after losing his biological mother to an incurable illness, his father remarried a beautiful stepmother, Hanae, and together with her daughter, Marie, they’ve been living a relatively happy life.

But one day, Tomonori discovers a shocking truth: his father, Seiichi, had been cheating on his late wife for years — and the other woman was none other than his current stepmother.

Tomonori had always resented his father, blaming him for his mother’s death. He believed her illness worsened because his father neglected the family. Yet he’d also tried to convince himself this resentment was misplaced — that his father must have grieved too. But he was wrong.

“Dad had been deceiving Mom the whole time she was sick.”

In terms of betrayal, his stepmother was just as guilty. After his mother’s death, she’d stepped into the role of the picture-perfect wife and mother, acting like nothing was wrong. All of it was a facade.

“I’ll take everything from Dad! Starting with stealing his beloved wife — and I’ll make sure he sees it!”

His feelings for his stepmother twisted into something dark, sparking a spiral of revenge and humiliation. Even as he knew this path would destroy their family — a point of no return — he kept going.

[Translated from the official site]