Kato was born on Altos Island, a place deep-rooted in a heavily religious culture. He and his twin, Odion Abara were forced into this religious activity by their mother and grew up under the idea that the deity of the island would be able to protect them as long as they were subservient to its wants and prayed to it.

Kato and Odion were inseparable from each other, spending all of their early childhood together. What their mother had failed to tell them was that per the islands tradition, at the yearly autumn festival, every decade a child of the age of 10 was sacrificed to the deity. Kato and Odion were both nervous and excited for the yearly ceremony, not even considering that they were both ten.
Kato was chosen.
Odion, enraged and panicked, decided to sacrifice himself instead of Kato, being killed upon the alter in the centre of their village.

Without his brother, Kato began hating the culture of their island, as much as his mother tried to persuade him that his brother's sacrifice was 'for the greater good' Kato came to the realisation that believing in deities was worthless. What was the point of caring for a god that only takes and never gives? Kato would become his own god, whatever it took.

As a child, Kato was energetic and fun, always having the energy to run and play with his twin. The pair were inseprable and Kato loved his brother very dearly. He didn't even particularly care about the deity that supposedly protected them, just going about daily life.

However, when he became the False God, he grew mad with power, now forcing the people of his island to worship him as the benevolent god he truly believes he is.