Rule 34 Dev - 1boy absurdres black_board brown_hair chair chalk chalkboard classroom figure_(medium) full_body genderswap genderswap_(ftm) grey_background highres male male_focus male_solo math navyobake onomichi_mion school_uniform short_hair shota shuukan_watashi_no_onii-chan solo standing_on_chair wiping wooden_floor|3419010942