Yamato is Ultimo's Master. When Ultimo woke up, Ultimo recognized him as the Yamato of the 12th Century. The 12th Century Yamato was a bandit stealing from the rich and he was the one that opened both Ultimo's and Vice's boxes. Even Ultimo noticed the appearances down to the expressions that the present Yamato and the 21st Century Yamato had are the same and therefore Ultimo concluded that Yamato is a reincarnation of the 21st Century Yamato.
Yamato is a high school student. His parents separated and his mother is taking care of him. He's best friends with Rune. His love interest is Sayama.
During the battle between Hana and Edile, Yamato decided that he would leave his whole class to go after Dunstan right after winning the fight.