1girl, armpits, arms_behind_head, bush, greyscale, hair_between_eyes, hair_ornament, hairclip, looking_at_viewer, lying, monochrome, on_back, open_mouth, original, pillow, short_hair, shorts, sleeveless, sleeveless_sweater, solo, sweater, teeth, thighs, twintails, upper_teeth_only, yamamoto_souichirou