FL has a scary face so her entire life everyone would be scared of her. Somehow she manages to get a job at a daycare, all the kids are scared of her but her coworkers are really nice except for the ML he is kind of distant towards her. She thinks its cus he's scared of her face but its not that, he's just naturally introverted. Anyway she ends up confronting him and makes a joke about marriage, and to her surprise he actually proposes to her. She thinks of it as a joke and just laughs, the next day the ML beings it up again and makes himself clear about not joking. The FL suggests they date first so they do. While dating the kids in the daycare start liking her! Anyway in the end they get married and even have kids, and in the final page the kids at the daycare visit them as teenagers.
Hosaka-sensei no Ai no Muchi