Mh mh, I understand... You know, I think that Aiba would be better playing a not so serious role... he's not this great actor, and he didn't acted much in the past, so he's not very versatile. I think that he should find a role that really suits him... and maybe this one in Mikeneko is the right one.
And honestly I haven't watched Ohkura's 'old things', so I really don't know about it... with him I only watched 8uppers, Ooku and Umareru O_O