hmmm my memory is kinda fuzzy but when i was young i remember watching an anime where there was a kid born inside a peach that was floating down the river... then later when he grow up he can transform into a samurai robot or sumtin =x

It might be Urusei Yatsura, as there is a character that comes to earth after flying in a spaceship inside a peach.


Or it's some adaptation of Momotarō.

________________
"Officially, this machine doesn't exist, you didn't get it from me,
and I don't know you. Make sure it doesn't leave the building."

=o I think it is an adaptation of Momotaro i just dont remember what the anime name is =[