He's employee of Korean company that bored and he play the dating app from there. He meet a lot people there but just for intrude their personality until one day he meet with y/n on that app. He's got interested with her until move into KakaoTalk. 
They talk a lot for 5 months and he confess about his feeling that make him and y/n dating. They do long distance relationship but he's so sweet, he often send messages about his daily, do the video call every night, also sometimes he send her package