Lovers High: Shinyuu no Kareshi to Matching shiteshimatta

Hikaru is a fourth-year university student who has no boyfriend and is having trouble finding a job. When her best friend finds her first boyfriend, Hikaru becomes impatient and starts using a dating app. She meets Kento, a handsome working man, and they hit it off and spend the night together.

Hikaru thought she was going to have a happy love life, but Kento is actually her best friend's boyfriend...?

(Source: Hakusensha, translated)