I Became A Captive Of My Step-grandson's Body: Suzuhana Ukyo

Ukyo Suzuka is a vibrant sexagenarian woman. Today, she's overjoyed to be heading to Tokyo to see her grandson Naoto for the first time in decades. However, Naoto, whom she hasn't seen since elementary school, has grown into a fine adult, and his lower half has also grown impressively. The vibrant sexagenarian can't help but feel a flutter for her grandson.