Starting from Scratch: Life with My Little Brother

After the Holy War ended, the Saints of the Twelve Houses were all revived by the goddess Athena, except for a little mishap with Gemini.

Saga, the Gemini Saint, remained at the peak of his strength at age twenty-eight, just as he had been before his death. But his twin brother Kanon had turned into a five-year-old child and was thrown into another world by an unknown god.

He had lost all memories of the Holy War, retaining only his childhood dependence on his older brother.

Saga followed him there, and could only make the best of things by taking care of his little brother and doting on him every day.

A few things to know before reading:

The only pairing is Saga/Kanon (there may be other Gemini-related incest, too).

The early story focuses on familial affection as Saga raises a child; the romance begins only after Kanon grows back up.

The only main plot is the sweet, child-raising fluff (with OOC) and returning to the Sanctuary.

Any anime or movies that appear are undecided.

Theme: Protecting Athena is the duty of every Saint.