Kazuma Hasebe is going nowhere fast, working multiple jobs just to make ends meet. After a bad day of gambling, he's skulking around town when he runs into Nao, the "hot girl" from back when he was still in school. She doesn't remember him. Actually, she's visibly disgusted at the sight of him, and when Nao's fiancé Takauji shows up he piles on the abuse as well. The whole traumatic experience transforms Kazuma into a stalker.

One day, while peeking into Nao's apartment, he gets into a tussle with Takauji and they take a fall down a flight of stairs. Nao hears the commotion and runs out to fuss over Takauji... but something is different.

Kazuma and Takauji have somehow swapped bodies! Takauji tries to explain the freak occurrence—but now he's the freak, and Nao won't even give him the time of day. Seeing a once-in-a-lifetime opportunity, Kazuma takes over as Takauji on the spot.

With a brand-new life in a brand-new body, what was once a living hell for Kazuma is now paradise on earth! But how will his love-hate relationship with Nao influence his new life decisions? And how long will his body swap even last...?

[From Johren]