Kanno Tsubaki, who works at a stationery store, cannot laugh in public. One day after work, a man helps Tsubaki who has dropped her glasses on the road and is stuck. The man was actually Touma, the next candidate for the Katsuragi family, who came to Tsubaki when her mother, Yuriko, who died when she was child, asked him to make her daughter laugh.

Tsubaki, whose glasses are broken and cannot move, is asked to take her back to the izakaya run by her father. So Touma heard from Tsubaki's father that Tsubaki stopped laughing because she found out when she was a high school student that her mother, who was lying dead, actually went out with another man...