koutaro, hinata hanabi, tropical kiss, game cg, 10s, 1boy, 1girl, ahoge, bikini, blush, bow, breasts, couple, fingering, fingering from behind, frilled bikini, frills, front-tie top, grabbing another's breast, groping, hair bow, hair intakes, hair ribbon, hetero, large breasts, nipples, open mouth, partially underwater shot, pink hair, polka dot, polka dot bikini, polka dot swimsuit, ponytail, pool, red eyes, ribbon, short hair, submerged, swimsuit, underwater, water