"Bijin de wo Kanemochi no Kanojo ga Hoshii" to Ittara, Wake Ari Joshi ga Yattekita Ken.

This is a slightly mature coming-of-age romantic comedy that questions what it means to be in love! Iori Shino (a virgin), a student at a university in Fukuoka, became engaged to Tsukasa Tendo, a famous girl on campus, because of an unintentional comment he made to his family. Iori's fiancée is beautiful and rich, but she was also rumored to be willing to "sleep with anyone". (Source: GC Novels, translated)