Rule 34 Dev - 1boy 1girl collared_shirt copyright_name from_behind grand_piano greyscale high_heels highres instrument long_hair mari_(faraway)_(omori) mari_(omori) monochrome music nishikigi0000 omori piano piano_bench playing_instrument playing_piano shirt short_hair short_sleeves shorts sitting socks sunny_(omori) sweater_vest|23166867789