Okay, so I believe I seen it in the early 2000's, it wasn't in english, it had subtitles. An asian (probably Japanese) like teenager was causing trouble for his family and stuff because he was schizophrenic or something, they put him into a mental hospital. He claims he can see a black dragon, and is always staring at the ceiling and stuff. Later he claims he is that dragon. He eventually stops speaking almost entirely. Later in the movie they let him out, he reconnects with his friends, and maybe his sister, I don't know. He gets an apartment with his friend, they don't furnish it, one day, in this empty apartment, he suggests they start a band, his friend is pretty excited at this change in him, and hopes that he's starting to feel himself, he procures the instruments. The main character gets a guitar, and starts practicing, and just plays the same note, over and over again, for days, eventually his friend gets upset, and fed up, maybe assaults him, but he just leaves him there. When the friend leaves, he finally stops playing, and just sits there in the dark, empty apartment, and just stares, blankly.