After the first concert ends, they seem to meet for dinner and drink beer.
Koichi: The children of MA is really weak with alcohol so they immediately blush red. Ah, except Akiyama. (He seperates Akiyama from the other 3 with his left hand) I'm white even if I drink.
The reason Akiyama doesn't blush is appearantly because he's a 'white guy'.
Akiyama: I'm white too. Since there's Caucasian blood, so..."
Koichi: I'm pure Japanese.
For some reason Koichi who said 'I'm white', someone from the audience said "Because you do not go out!" but it was ignored. (But that's totally true.)