"Gojo Toma," the adopted son of the Nagareki family.
He lost his parents at a young age, and now spends his happy days with his childhood friend Nagareki Himka and the others.
One day, he sees a red dream.
Two tiny figures.
A girl with black hair,
and a boy with blue eyes.

"I have a favor to ask of you."
"...What?"

—That is the primal scene that remains in his memory.