"Bijin de Okanemochi no Kanojo ga Hoshii" to Ittara, Wakeari Joshi ga Yattekita Ken.

Iori Shino (virgin), a college student in Fukuoka, becomes engaged to Tsukasa Tendou, a well-known celebrity on campus, because of an unintentional comment he made to his family. She is a beauty and rich—however, Iori is put off by his fiancée, who is rumored to "sleep with anyone," and Tsukasa is aggressively coming onto him... where will their future go?! This is the start of a "slightly mature" romantic comedy of a breaking-off-engagement genre that questions the meaning of falling in love!!

(Source: Micro Magazine-sha, translated)