Kids Return (1996)

Two school-age chums, Shinji and Masaru, spend most of their school days harassing fellow classmates, playing pranks, and sneaking to the movies. They decide to drop out and gain their fortunes in the outside world. Shinji becomes a small-time boxer, while Masaru joins up with a local Yakuza gang. Over the years the two do well, but their undisciplined nature comes back to haunt them.