Well, Mikami would remain civil if at all possible. Although the degree of control that would take depends on the person and the situation. Like, lower ranking members of red or green he'd be civil but not pleasant. Now, if he were to run into a high ranking member of either clan it would take a whole hell of a lot of control. He wouldn't fight unless yet started it or were doing something criminal, because Mikami prides himself on knowing exactly how many laws he is braking at any given time. Gold he gets along with just fine.

Tadashi would flirt with them if they were attractive and of age. He doesn't harbor much resentment towards other clans.