Takehiko Yoichi is the class representative for Mahiro Yasaka, Nyaruko, Kūko, and Hasuta. He presents as a human teenager with short gray hair styled to his ears, gray eyes, and is typically seen wearing glasses and his school uniform complete with a tie.

He's Mahiro Yasaka's friend, often offering him advice and support during school situations. Primarily interacting within the school setting, he observes and occasionally comments on the unusual dynamics caused by his classmates' alien antics.