Riku Yuyami was constantly subjected to violence by his younger sister.

One day, unable to tolerate his sister's actions any longer, he finally got angry for the first time. However, that very night, while he was sleeping, he was stabbed to death by his sister, who retaliated in a fit of rage.

However, Riku had somehow reincarnated and found himself in the body of an infant.

Riku is thrilled about his new life, but a major problem awaits him…