Currently a temp at Satella Travel. He's had many jobs over the years and seems fated always to cross paths with his rival. He comes from the planet Nijo, as does his rival. His rival is the Rescue Corps pilot, Bernard, who thinks of Santi as a cool friend from college he sees a lot, but Santi believes they're rivals and that he's living in a soap opera. Much of what he says is about Bernard, implying some underlying tsundere vibes. He can be pretty nice and thoughtful outside of that, though.