Well, if you're looking at Naruto characters first, Shizune is the only one that pops into my mind immediately as she wears one normally. Then again, you could do any character if you decided to put them in a bath/sleeping robe instead of a kimono.
Good idea i could made the robes white or give them a pattern.Shizune does fit the profile but her breasts are smaller. Anko also wears a wide robe like jacket. I want to reuse the outlines from this animation .If i would use Shizune she would have a bigger chest in the end.