The story was interesting. I dont wanna be jumped at but I think the black haired one has autism. He is a bit out of loop and understand things differently bu once he understood his feelings he just went all out.
But the ending was so rushed. There are a lot of unfinished story arcs that wasnt addressed properly. Like them planning to study abroad, the result of the argument with the brown haired boy and his father and cementing the fact that the black haired boy understood his feelings and made their relationship clear. And also what was their friend and blond haired hyung's reaction.
Ah, so many questions left unanswered ...