Uhhhhm Kiryu leaves the clan cuz his crime could harm it and he didn't want that because he respects the leader who is in prison. So he joins that nip with prosthetics and fight against his ex clan for that spot.
Majima and the guy he works for also want it so they all beat each other for it.
I forgot what happens in the ending though, I beat the guy with glasses then ugh... I forgot anyways something happens then Majima and Kiryu meet.
Yeah that's pretty much it. Stop testing my memory you know how shit it is.