kouzaka kouhei, kamimura chika, kamimura haruka, comiket, comiket 70, sisters ~natsu no saigo no hi~, official art, photo (medium), 1boy, 2girls, :d, adjusting hair, aqua eyes, arm support, arm up, armpits, ass, bag, bikini, black hair, blue eyes, blush, breasts, brown hair, cleavage, clenched hand, covered erect nipples, green eyes, hair between eyes, hair ornament, hair tubes, hairclip, inflatable raft, jellyfish, kneepits, large breasts, legs, long hair, looking at viewer, looking back, lying, multiple girls, on side, one-piece swimsuit, open mouth, orange hair, outdoors, panties, road, school swimsuit, shiny skin, shoes, short hair, short twintails, siblings, side-tie bikini bottom, sidelocks, sisters, smile, sneakers, sports bikini, street, swept bangs, swimsuit, twintails, two side up, underwear, white bikini