1boy, 1girl, arms_up, ass, blue_theme, blush, breasts, comic, fate/grand_order, fate_(series), fujimaru_ritsuka_(male), glasses, hand_on_own_chest, koyuki_(kotatsu358), large_breasts, mash_kyrielight, monochrome, one-piece_swimsuit, open_mouth, school_swimsuit, school_uniform, speech_bubble, swimsuit, swimsuit_under_clothes, undressing