I see a lot of people justifying the age gap and I wanna say what in the world is wrong with you. The thing is this story could have had the same feel if the male lead was legal. If the point was of this storyline was to show a contrast in age and gender roles, they could have made the lead A freshman at Uni. It would have still given him a naive vibe and it would have still made society judge her, but he would have been an adult. Yes, it's still a bit weird, but he would have been doing adult things at that time and have adult responsibilities. For the story's sake, he would have still been super young and hardly an adult, but he would be one that can consent.
If they "had to make him 15"( No) they should have actually shown the signs of abuse boys go through when an adult is grooming them. The main highlight of this story should have been how wrong she is and how she's going down a spiral of darkness. The show makes it seem like she's just going thru a sad phase in life and this KID is there for her...NO. It does romanticize their relationship and it focuses on it too much almost saying "this is wrong and illegal... but should it be, because we "love" each other". Like what.. She should have faced ACTUAL consequences to show how serious, wrong, reckless their relationship was. I wish it showed his inner feelings and inn turmoil from the harsh reality of a relationship like that. The main female character is weak, narcissistic, and pathetic. The storyline is lazy.
It is not a complex storyline. This is no different from a story like Lolita. I'm glad all actors/actresses are at least legal though.

I gave the acting and music high ratings is because the acting was technically good and so was the music. I wish everything else could be given a zero.