Kids Return is a film directed by my favourite contemporary Japanese director 'Beat' Takeshi Kitano though only recently have I gotten round to watching it. For people who think they've never heard of or seen him in a film, they most likely have given that he's 'Takeshi' from the TV Show 'Takeshi's Castle' and he also plays the teacher in Battle Royale. His films are usually backed up with scores from Joe Hisaishi who does all Studio Ghibli/Miyazaki soundtracks.
Anyway Kids Return is brilliant, probably jumping somewhere near to the top of list of favourite Kitano films. Almost all of Kitano's films deal with in some way impossible friendships and relationship that simply cannot last though an eternal bond is always forged. Oh and his films almost always feature Yakuza in some form. Kids Return is the same though it ends on slightly more positive if still downbeat note. It's not really something you can describe and make it sound as interesting as it actually. It's just a film about two close friends who begin to drift as far away but still stay connected. One becomes a promising Boxer the other a promising Yakuza, both careers end in the same results. Watch the trailer and then watch some of his films, I guarantee there's nothing else quite like them in the entire world of cinema.
Also recommended are Boiling Point, Sonatine, Hana-bi and Kikujiro. Dolls as well if you're up for some weird arty non-sense. Basically all his films are interesting but the ones above are the ones I consider the strongest examples his style of film making.