Get drunk, fall in love, graduate

Kyeong Mi-rae, on her assumed birthday has nothing else to do. Growing up with no friends or any support has made her callous and closed off.
She decides to go to a nightclub for the first time, in an attempt to have fun alone.
While having too much to drink, she runs off to the bathroom. But she witnesses a man and a woman making out.

Confused and nauseas, she ends up throwing up on the floor. As she slowly passes out and wakes up, she finds herself in an apartment. Not knowing what to do, she pretends to sleep when she hears a man's footsteps...

This novel is in the perspective of a recovering adult alcoholic, telling the story of her last year of high school and what led up to it.

Based in japan even tho I've never been there lol