Amon's behavior changed when he unlocked his unique "Fury" genetics at the age of 5.
After living with his grandparents for 11 years, he learned to behave properly.
However, his grandparents faked their deaths and he had to move in with his mother, stepfather, and non-biological twin sisters, and attend a new school, presenting a new challenge for him.
If you don't like a harem and R-18 chapters this novel is not for you.