1girl, arms_behind_head, arms_up, blush, grey_sailor_collar, grey_skirt, hair_tie_in_mouth, kutatsu_(kutatsu7), looking_at_viewer, mouth_hold, navel, neckerchief, original, pleated_skirt, ponytail, sailor_collar, school_uniform, serafuku, shirt, skirt, solo, stomach, uniform, white_shirt