Heard of this band recently - they started as an Oi! band in the late 80's (some even consider them the best Japanese Oi! act which I can't confirm cause I haven't listened to many Japanese bands anyway). Then, by the mid 90's, they changed their sound to more indie/emo type of punk rock. Still very good and original.
Check out this song, it's my favorite so far. Sounds as a mixture of Oi! and the multi-layered melodic punk of bands like Husker Du and Leatherface.
Oi! Oi!