[Hikoma Hiroyuki] Gaki Ana ni Okusuri Tsukatte Kuppuku Onaho Kyouiku [MTL]

A shy young girl named Mana discovers she can finally fit a thick toy inside her virgin body, sparking a secret training with her peers that pushes her toward submission. Guided by older boys who test her limits, she endures intense stimulation that leaves her slick and eager, while the promise of 'special medicine' fuels their obsessive lessons. The story builds a tense, erotic dynamic as each encounter deepens her obedience and the stakes of her transformation.