The legendary boy raised on Mount Ashigara who became a strong warrior was Kintarō.
Kintarō, or “Golden Boy,” is a Japanese folk hero celebrated for extraordinary strength from childhood. Stories place his upbringing on Mount Ashigara, where he lived among mountain animals and performed feats such as uprooting trees, breaking rocks, and wrestling bears or giant carp. He is commonly shown wearing a red apron marked with the character for “gold” and carrying a large axe.
The details of his childhood vary. In some versions, his mother raises him in the mountains; in others, he is brought up by the yama-uba, a supernatural mountain woman. One especially fanciful account connects his birth to lightning and a red dragon associated with Mount Ashigara.
As an adult, Kintarō takes the name Sakata no Kintoki and becomes a retainer of Minamoto no Yorimitsu, also called Raikō. He joins Yorimitsu’s celebrated Shitennō, or “Four Braves,” and becomes a warrior figure in kabuki, bunraku, children’s stories, and Boy’s Day traditions.