During the Edo period, the gods tasked Momotaro with exterminating demons that possessed and drained human life force with parasitic "bugs." Alongside his loyal vassals—Kensuke, Saruhiko, and Yukijiro—Momotaro fought valiantly until one day, a powerful demon nearly annihilated them all. On the verge of death, a god spoke out: "Momotaro, you must strike that demon down. Power will accumulate in a peach from which you shall be reborn. Choose a vassal whom I'll make immortal to protect you during your slumber."

Centuries later, in the modern Reiwa era, the newly reincarnated Momotaro awakens... in the body of a chicken?!