At first glance, the setting is an ordinary school. However, the school has a "Shinobi Group" that is only allowed to operate at night.

The protagonist, Kyoichi, was born into a ninja family and was one of the students in the "Shinobi Group". However, Kyoichi does not like his ninja bloodline and lives a careless student life...

One day, an incident occurs that shakes up this life. It is said that Mayuko, a girl whom Kyoichi has admired for a long time, is in danger. The mastermind behind this is the school's dean.

"Return to the Female Body" ---

A ninjutsu that has now become an illusion, and was no longer thought to exist. It seems that the school dean, who was on the verge of death, activated a secret technique called "to be reborn in this world while retaining the memories of his previous life.''

"A fetus with memories"...

Mayuko was chosen as the "mother" to give birth to this fetus. For Mayuko's sake, Kyouichi decides to become a "ninja", something he detests. Will Kyouichi be able to protect Mayuko?

Or will he....

"A fierce ninjutsu battle with the attacking assassins begins!"

[Translated from the the official site]