1girl, blonde_hair, bracelet, brown_eyes, casual_one-piece_swimsuit, day, earrings, flower, frilled_one-piece_swimsuit, frills, from_behind, genderswap, genderswap_(mtf), hair_flower, hair_ornament, hair_tie, halterneck, hand_on_own_knee, jewelry, long_hair, looking_at_viewer, looking_back, low_twintails, one-piece_swimsuit, onii-chan_wa_oshimai!, open_mouth, oyama_mahiro, peteron, poolside, ribbon, sitting, smile, soaking_feet, solo, swimsuit, twintails, twitter_username, waving, wrist_ribbon, yellow_one-piece_swimsuit