Asuku Medix is a reincarnated boy who remembers his past life, where he died young from illness.

To prevent others from ending up like he did, Asuku wears a handmade plague mask and a black coat, spending his days secretly healing anyone hurt or sick on the streets.

One day, something happens.

His older sister, Franc, tells him that the twin princesses of the kingdom have fallen ill with a mysterious illness.

Asuku immediately heads to the royal capital.

He sneaks into the royal castle and secretly cures the princesses’ illness, but the moment he leaves, the entire kingdom launches a massive search for the unknown healer…