monogatari (series), nisemonogatari
araragi karen, araragi koyomi
yami shigeru
1boy, 1girl, ahoge, black hair, blush, brother and sister, grey eyes, hetero, incest, jacket, penis, sex, short hair, siblings, side ponytail, straddling, track jacket, upright straddle, veins, veiny penis, x-ray
commentary request