I apologize in advance for literally knowing nothing about this movie! It’s an anime movie, that was on TV about 7 years ago, I believe on Toonami. The only thing that I can remember about the movie is the shy boy and the very confident girl who sit on the edge of an aqueduct. There is the only scene I remember where they are in the boys room and the girl sits on his lap while he is laying down. He becomes aroused and there is a red arrow pointing down towards where the girl is sitting indicating this. She takes notice of this and laughs while he is very embarrassed and freaks out.. Again, I apologize as this is the only information I can remember!