akira hamaguchi, darling in the franxx, effects, liquid, 1girl, hiro (darling in the franxx), 1boy, zero two (darling in the franxx), long hair, pink hair, closed eyes, black hair, horns, anime coloring, clenched teeth, swimsuit, oni horns, hetero, couple, one-piece swimsuit, teeth, collarbone, bangs, water, hairband, red horns, ponytail, white hairband