hmm, I’ve heard of Beastars, but what’s this Sanda?

The story takes place in the future, where the birth rate in Japan has been rapidly declining. The main character, Kazushige Sanda, is found to be the descendant of Santa Claus by his classmate, Shiori Fuyumura. Together, they attempt to find Fuyumura’s missing classmate, Ono Ichie.