I read two theories online. One says he died due to extreme exhaustion from part-time jobs, while the other says he died because of a head injury.
Personally, I lean toward the second theory. The evidence is that in the last ten minutes of the film, after the main character finished his conversation with his bf mother, he went to a vending machine to buy a bottle of water. When he crouched down to pick it up, he dropped his coins. As he bent to collect them, he bit down hard on his wrist and cried intensely. Most likely, this scene shows that he was recalling memories with his lover at the beginning of the film, when he dropped coins in the cafeteria, which triggered his sadness.
Watched the whole thing and still can’t see the chemistry she should’ve ended up with the second male lead
Personally, I lean toward the second theory. The evidence is that in the last ten minutes of the film, after the main character finished his conversation with his bf mother, he went to a vending machine to buy a bottle of water. When he crouched down to pick it up, he dropped his coins. As he bent to collect them, he bit down hard on his wrist and cried intensely. Most likely, this scene shows that he was recalling memories with his lover at the beginning of the film, when he dropped coins in the cafeteria, which triggered his sadness.