1boy, 1girl, a tea, ahoge, arknights, arms behind back, bikini, bound, bound arms, chinese text, doctor (arknights), goggles, goggles around neck, greyscale, helmet, hood, hoodie, la pluma (arknights), la pluma (summer flowers) (arknights), monochrome, navel, official alternate costume, rope, shibari, short hair, shorts, swimsuit, thigh strap, tying