Kazuo

Kazuo is the eldest brother of the Ozawa family. He was mentioned in Battle High: Elemental Revolt, and made his playable debut in Battle High 2.

Battle High 2
Kazuo is Jiro's long forgotten twin brother. After a violent outburst against his youngest sibling, Shinji, Kazuo was sent to a boarding school and was soon forgotten about, his parents refusing to even say his name. As the years went on, the powerful earth elemental grew angry at his entire family, but particularly Shinji, believing he was the cause of all his problems. With a never-dying grudge and unable to be stopped, Kazuo left the boarding school he was banished to and returned to San Bruno to find his brothers for a "pleasant" reunion.