Wataru Kodera was fired from his job after a complaint of misconduct.
He'd been falsely accused of groping by a coworker. Her name was Akane Nakazono.

Wondering how he might get back at her,
Wataru happened to see Akane on the train, and rage erupted from his core.
He relished doing his first criminal deed to a woman who claimed
he'd already done it. But was this poetic retribution of a good man with nothing to lose,
or an excuse to unleash the wickedness that he was harboring all along?

In either case, Wataru would have revenge.

[From DLsite English]