1990s_(style), 1girl, ;p, arm_behind_head, arm_up, beach_chair, bikini, blue_bikini, book, brown_hair, covering_navel, holding, holding_book, kai_tomohisa, looking_at_viewer, lying, on_back, one_eye_closed, photoshop_(medium), retro_artstyle, sentimental_graffiti, short_hair, simple_background, solo, sunglasses, swimsuit, tongue, tongue_out, white_background, yamamoto_rurika