Kuroudo Tamaki, a weary and uninspired middle-aged office worker, has become the butt of everyone’s jokes—a man dismissed as a hopeless case. Mocked for his growing belly, ignored by his own daughter, and then one day, he happens to see something unsettling on his wife’s phone: a string of suspicious calls with one of her coworkers.
As his miserable routine drags on, his efficient junior colleague, Mizuki Ayase, suddenly calls him to the storage room for assistance. While helping her move some equipment, his hand accidentally brushes against her chest—and she captures the moment on video. Later that day, Tamaki finds himself being blackmailed with the footage, leading him unexpectedly to… a gym?
Could the punishment for sexual harassment really be physical training? Thus begins a secret, muscle-building comedy of self-reinvention that he must keep hidden from his wife!