"Is that feeling a curse or love?"

A strange calamity known as the "Fallen Child" has appeared in Kamimizu-ryu.
There are those who resist the unprecedented crises that have repeatedly befallen them, among those there are Itsukino Naoya, Hinamori Saya, Itsukino Ichika and Fujinomiya Atsushi.

They perform a "Purification Ritual" to subdue the Fallen Child, however,
the "Purification Ritual" comes with a cursed "price".

"We have confirmed the Seahorse invasion. We will now subdue the breach of our territory."

With the Fallen Child looming before his very eyes, Naoya wields his "immortal power."
With each battle and each defense, more losses follow.
Yet, his resolve to protect his town and his comrades remains unwavering, even if it means losing something more precious than his own life.

"I won't let that happen."

A strange girl appears before Naoya, who is giving everything he's got and pushing forward towards his destiny.
But the girl knows something... she has come all the way here to meet him.

"This time, I will save you."
"Even if you hate me..."

The Blue Witch, Kasumi Yuuki.
Meeting her will change Naoya's destiny.

[Translated and edited from DMM]