He is the lawyer of the Ryuusei clan
Oh shit....
I don't think that is the lawyer Shirasu. This new guy's face looks different, more delicate. http://www.mangago.zone/read-manga/kuchizuke_wa_uso_no_aji/bt/sa-v3c003/pg-1/?av=1
he looks younger than the lawyer. The lawyer must be in his 40's since he and the 2nd head of the clan goes way back.
Yeah something about then doesn't match 100% but they definitely have the same eyebrows. Maybe a younger brother?
Oh I like that theory!
Okay, does somebody recognize the guy who waited for Igarashi (the "uncle") in the car? For me he looks like the lawyer of the Ryuusei clan. But that would be to huge a blow for team Makio, no?