Hiro is a broke, unemployed, and habitually unfaithful young man who views women as convenient sources of money and attention. His latest girlfriend, Mii-chan, is a woman with a catastrophically poor track record with men: she has never had a relationship last longer than a week, has been stood up for days at a time, and has been financially taken advantage of by previous partners. This has driven her standards for a boyfriend so low that Hiro’s bare-minimum decency — remembering her name, showing up for dates, staying together for more than a week — seems like ideal boyfriend material to her. Hiro initially sees her as an easy mark and plans to dump her as soon as it becomes convenient, but hearing her horrifying dating history triggers an unexpected sense of guilt. He finds himself unable to act the full scumbag he normally would, and instead begins to develop a protective, if bewildered, attachment to her.

The story unfolds in a contemporary Japanese city and uses a short-gag format to follow the daily life of this mismatched couple. Mii-chan is sweet, clingy, and dangerously devoted — she once set her credit card PIN to Hiro’s birthday — while Hiro is a self-aware scoundrel who repeatedly fails to follow through on his worst impulses. Their dynamic flips the usual rom‑com power balance: the supposed “scum” becomes the one who is constantly thrown off by his girlfriend’s oblivious low expectations. A major early arc involves Hiro deciding that, since he cannot bring himself to dump her, he will find her a new boyfriend worthy of her. His search is complicated by his own unexpected jealousy and by the fact that he is skilled at spotting other scumbags. The only seemingly decent candidate turns out to be Mii-chan’s abusive ex‑boyfriend, now a stalker determined to win her back. This forces Hiro to step up in a way he never anticipated, culminating in his shocking declaration that he will get a job — a first in his adult life — simply because he wants to “be together with her more.” The third volume brings this conflict to a head, with Hiro going to work both to support her and to confront the stalker ex.

Additional minor characters include Hiro’s friends — a host and a man supported by seven different women — who provide contrast and comic relief. The series keeps its focus tightly on the central couple, gradually revealing Mii‑chan’s past (her real name is Minori) and the real reason she loves a man everyone else would call trash: because, in her experience, even minimal reliability is nothing short of a miracle. The narrative balances laugh‑out‑loud moments with genuine emotional beats as Hiro’s conscience slowly erodes his cynicism, and as Mii‑chan’s overwhelming love begins to change him in ways neither of them expected.