er.... I don't think this is Kaguya. Kaguya has black to brown eyes and obviously black hair.
It's more likely that the character here is Byakuren, who has yellow eyes and somewhat brown hair (also note the slight fade on or her hair here).

According to the artist's page, it's Marisa after she tries some conditioner she bought from Kourin.

Jakki said:
According to the artist's page, it's Marisa after she tries some conditioner she bought from Kourin.

So that's why they put Rinnosuke in the back :D

Darksheeth said:
So that's why they put Rinnosuke in the back :D

Kinda surprised Alice isn't there