Dam I bumped the send button I was going to finish with Hanzo being accused as a spy but a dark figure hidden in the shadows behind him and carried inside
There he'd meet the 7 Masters of the Aoi yane no jiin (Temple of the Blue Roof)
It's an old fighting temple where they used to train warrior monks but it was abandoned till several years ago it was found by the present masters who seek new worthy disciples, the only problem is that they keep breaking them.
The girl is from Okinawa and she lost to the masters when she challenged them to a fight and as her end of the bet she had to become their disciple
Hanzo as an interloper will be offered a chance to join their dojo or be beaten without mercy; of course if he joins he'll also be beaten without mercy but the difference will be that the Latter one they will use to teach him martial arts.
The others could join because Hanzo knows them from school or they could stumble down the street and hear the noise of Hanzo an Yuki being beaten and investigate

I'd suggest that each player create one of the 7 masters each as part of the task to join the rp and latter we can each create a bad boy or girl to play as an Npc but remember that the Npc is meant only to be tough to beat but they are meant to be beaten