Hayami is the it-woman at her job—she’s cool, confident, and admired by all. But her has-it-all exterior belies a dark secret...her house is a mess, and she's no good at taking care of herself! Enter Yamamoto-kun—her colleague who thinks the world of her, and who refuses to let her slobbish behavior slide. Soon he’s over at her house often enough that she asks him to move in with her! Where will this roundabout relationship take them?!
At 27 years old, Hayami is “the perfect sempai,” but at home she becomes a massive slob. It just so happens that her junior, Yamamoto-kun, is a pro at housework! Hayami takes him in as her wife, and over time, they go from being housemates to boyfriend and girlfriend. After finding out Yamamoto-kun’s got marriage on the brain, Hayami takes the plunge with a proposal! Things heat up even more when Hayami meets her mother-in-law-to-be, whose charms drive a massive wedge between the two lovebirds. But life doesn’t end at “I do”; the two have a long and happy road ahead of them!