The only adult member of the 'Idol' team, Casio is their guardian, technician, and confidant rolled into one. A former Topless himself (he was a pilot of Dix-Neuf before Lal'C joined the Fraternity), Casio possesses an intimate understanding of the workings of the Buster Machines, as well as the people forced to pilot them. That is part of why he was one of the first to express his doubts on Nicola's assertion that Nono had the potential to become a pilot. Despite his initial misgivings, however, he joins Lal'C in welcoming Nono into their 'team'.
Despite being a lech and a joker, Casio can be surprisingly serious when the situation merits it. He secretly yearns to pilot a Buster Machine again, but is resigned to the fact that he can only be near them, due to his advanced age.