As for the GF, after some stuff between Kurosawa, Ozu and Hara, then Ozu's sis, Ozu confessed he loves her, then GF returns from England, turns out her grandmother is very sick and she'd like to see her wedding before she passes on, but stuff happens, because of Ozu's feelings and they eventually break up. By the way, GF didn't cheat in the series, but she's clingy as hell, and won't give up easily, also she is in love with Ozu. Also Ozu's friend comes to like Hara, and there will be some drama on that department as well, and a falling out between the 2 guys.