Office worker Momoka is up against a tight deadline, working on important documents at home when a gust of wind sweeps them onto the neighboring balcony. Panic sets in because the neighbor is none other than her strict, intimidating boss, Kouichi. Forced to retrieve the papers, she sneaks onto his veranda and accidentally stumbles into a compromising and private moment with him. Instead of the cold, professional demeanor she knows from the office, Kouichi transforms into an intensely passionate and possessive man, declaring that a disobedient subordinate deserves punishment. This encounter ignites a secret, heated relationship between them that blurs the lines between work and personal life.

Momoka is an earnest and somewhat flustered employee who finds herself torn between her professional respect for her superior and the overwhelming desire he awakens in her. Kouichi, known as a demon boss at work, hides a fiercely passionate and beastly nature that emerges once they are behind closed doors or out of office hours. Their dynamic deepens as they navigate a secret romance filled with tension, with Kouichi showing an unexpectedly tender side alongside his possessive streak.

As their relationship develops, new complications arise. A company marathon event leads to training sessions and massages that quickly become charged with romantic affection. The arrival of Sota, the handsome and mysterious apartment manager who also takes an interest in Momoka, introduces a love triangle. Sota's awareness of Momoka and Kouichi's relationship stokes Kouichi's jealousy, culminating in a tense confrontation at the marathon. Later story arcs follow them on a business trip where Momoka reaffirms her deepening love and experiences a growing sense of possessiveness, while Kouichi's overwhelming affection only intensifies, leading to dramatic and openly possessive declarations.