Naoto lives in an orphanage with friends along with the owner"s daughter, Ruriko. Orphanage is to be closed because of a debt. At the last excursion to the zoo, while Naoto makes a vow to become as strong as a tiger, Mister X offers to train Naoto… When Naoto grows up strong, he fights to protect the woman he loves, to save the children"s future and to pursue his chosen path.
