2boys, ass, back, bara, boxer_briefs, couple, from_above, greyscale, happy, kekkai_sensen, klaus_von_reinhertz, leonardo_watch, lying, lying_on_person, male_focus, male_underwear, monochrome, multiple_boys, muscular, muscular_male, nore_(boosuke), on_back, on_bed, shoes, short_hair, size_difference, sketch, smile, thighs, topless_male, underwear, yaoi