He didn't quit school in the original. He just took time off. Same thing here - Hajoon is just taking some time off to heal after the damage caused to him by the MC.
Wow your got quite the charming mc here, you made me care for a fanfic mc, that's impressive, good to see that decent writers like you are still in this site, the shjt we get here is so low quality that it hurts to read so nice to see quality stories are still blessing this site