I mean, her ex told her about how he fucked a bunch of girls in Tokyo and still think she's the best and really expect that she will fall in his arms after such "pure confession"? And this excuses like "I dumped you to earn money for us" - no, dude, you did it for yourself, it was self pity bcs you was broke and don't want her to think about you this way, but you didn't even think for a second that she was with you bcs she didn't care. No, you just cover your ass and ran away. I really hate such an egoist type of characters.
Maybe boy is stupid, but he need no proof of his feelings, and only idiot would think that if they are not dating (yet) he can't care about her and stood by her side. That what "care about" meens, friends or lovers or relatives or co-workers - care about someone is the same in all forms of relationships.