The Lost Prince: Lion Of The Watch Book One

Wolves of the beyond/ The Lion King, however you don't have to read WOTB to understand this.

Simba and Nala have a daughter; Kiara. They also have another cub, one who was born before Kiara,
a son.... and his name is Kopa.
Why do very few people know of Kopa?
Because he drowned saving his best friend Vitani.... or did he?
Before he could drown, a Grizzly Bear rescues him and takes him to a land where mountains spew fire and into the sky and dire wolves keep watch over them.
The dire wolves take Kopa in, and teach him how to be a Watch Wo- er, Watch Lion. Kopa is a natural at guarding the volcanoes, to the point that he trains other wolves how.
But why doesn't Kopa go back to his family?
It's because he doesn't remember anything.