1girl, arms_behind_back, bikini, bikini_bottom_only, black_hair, border, breasts, from_side, groin, hibike!_euphonium, kitauji_high_school_uniform, kousaka_reina, long_hair, looking_at_viewer, medium_breasts, nagayori, navel, neckerchief, no_pants, parted_lips, pink_neckerchief, polka_dot, polka_dot_bikini, sailor_collar, school_uniform, serafuku, shirt, short_sleeves, side-tie_bikini_bottom, solo, swimsuit, thighs, white_border, white_shirt