Mysterious Boy (a Pokémon fanfic)

Ippei and Nihei are two of the strongest siblings in all of Ninja Village, even though they weren't born in the village. One day they are sent out on a mission, when coming back they find a young boy, who looks a bit like their mother, passed out by the river, with a Froakie next to him. Who is this boy? What connection does he have to their mother? Will the boy be able to answer any of their questions?