akira hamaguchi, darling in the franxx, effects, liquid, hiro (darling in the franxx), 1girl, 1boy, zero two (darling in the franxx), pink hair, topless male, black hair, horns, long hair, cloud, sky, swimsuit, one-piece swimsuit, water, ponytail, oni horns, red horns, hetero, couple, day, anime coloring, blue sky, looking at another, cloudy sky, partially submerged, hairband, open mouth, alternate hairstyle, white hairband