SumiTheCat wrote: well... my boss my hero (yakuza), and Yankee Bokou ni Kaeru (SP) (yankee) are on your PTW list
similar to Gokusen : Misaki Number one
with yankees too : Tumbling (one of my fav), and i would also suggest Kisarazu Cat's eyes though it doesn't take place at school.
maybe the special : Mou Yuukai Nante Shinai (yakuza if I remember well).
I would definetly recommend Ninkyo Helper (yakuza) though it may not fit your criteria. but it remains one of the J-dramas that stroke me the most.
I heard a lot about tumbling, but I didn't know it was yankee related, because my friends who were obsessed with it, had nothing to do with yankee or yakuza.
I looked at them and there are a few I would give a try :D