[upanishi.] Girl Rapidly Grows Up During a 10-Second Countdown and Milks You Out of Curiosity [JusenkyoTL]

When Mina, a petite girl with a ponytail, erupts into a towering, voluptuous woman during a ten‑second countdown, she teases the shy boy Hiro‑kun with a bold promise to become his girlfriend, then straddles him, her massive breasts and eager body filling the frame as they share an intense, mutually curious encounter that leaves both breathless and questioning whether it was a dream.