First Love Number?

Min-Seo is a long-term student on leave who, having left behind a childhood of privilege and parental love, is now struggling on his own. Upon reuniting with Chae-Hui, whom he had a crush on in elementary school, Min-Seo is forced to confront how much his circumstances have changed. Unable to read the stoic Chae-Hui’s true intentions, Hwan—disguised as a good friend—is quietly tightening the noose around Min-Seo without his knowledge...

(Source: Bomtoon, translated)