Mizuda

is a high school student who attends Saint Ishiyama Academy. He has participated in the school's special event, Saint Saint X'mas, with a fellow high school student, Morikawa.

Saint Saint X'mas Arc
Mizuda and Morikawa participate in the Saint Saint X'mas competition together where they advance to the Top 16. In the first round, they are selected to go ninth, pairing off against the Tōjō-Shizuka pairing; ultimately, they end up losing in the first round.

Morikawa
Mizuda and Morikawa participated together in a Saint Saint X'mas competition on Christmas Eve.