Jin is the heir to his family shrine, secretly in love with his childhood friend Misaki but unable to admit his true feelings. To help him release his pent-up energy, a senior club member lends him a toy from a personal collection. Jin begins using this toy daily to act out his desires for Misaki, but the object is not ordinary. It moves and feels completely real. Through some miracle or curse, it is directly connected to Misaki herself. Every time Jin uses the toy, Misaki experiences the same sensations and is sexually tormented, unaware of the cause.

The story follows Jin and Misaki as they navigate this strange connection. Eventually, their feelings become mutual and they officially become a couple. Their mutual desire grows without restraint, leading to days spent constantly seeking each other out. However, one concern remains. The toy is still connected to Misaki, specifically to her rear. When Jin expresses his anxiety about this ongoing link, a senior named Sakaki suggests it might mean their hearts are not yet fully connected. This sets the stage for further exploration of whether the toy can truly connect more than just their bodies and what it will take for the pair to achieve complete union.