罰ゲームで嘘告をしたのだが、相手は同棲中の俺の許嫁でした (Associated Names)

The story follows the protagonist, a socially awkward high school boy with almost no friends, who one day is forced to confess his “love” to the most beautiful girl in school as part of a punishment game. However, the girl turns out to be none other than his fiancée, a fact they’ve been keeping secret…