Sigh. 
I can tell y'all what's gonna happen next and save you the suspense.
Yamada will think "Oh noes the orders of a hierarchical superior are absolute!" and will not object to the race. Then Kase will race Fukami and win. Then Yamada will jump into her arms and kiss her or something. Then and only then will Fukami and the others find out that Yamada is Kase's girlfriend! (In other words, that Kase wasn't planning to move in with some random homie but with her LOVER!) Then Fukami will hit Kase on the noggin and tell her she's got to be stupider than a monkey to bet her future with the woman she loves in a motherfucking race. And then, only then, Kase will be enlightened.