Azusa is the father of Yosho, Ayeka, and Sasami, and serves as head of House Masaki—though his wife Funaho effectively runs things while he's occupied with the throne of Jurai. He's best known for his disapproving attitude toward Ayeka's feelings for Tenchi, and he has a habit of seriously underestimating what Tenchi is actually capable of.
He doesn't get much screen time. Fans mainly see him in OVA episode 13, with brief appearances in a couple of Tenchi Muyo! GXP episodes. In GXP, he shows up at Kiriko Masaki's bonding ceremony alongside his close friend Utsutsumi Kamiki (who's married to Seto), and later appears with both his wives, Funaho and Misaki, when Seina Yamada officially becomes part of Jurai's royal line.
Content compiled by AnimeList.moe from publicly available sources.