Sodachi Oikura

老倉育, Euler

Araragi's childhood friend. She is a student with a strong sense of competitiveness which led to her popular nickname, much to her chagrin.

Sodachi was the president of a first-year class where both Hitagi and Koyomi also belonged to. At school, she wanted to be called as "Euler", but ends up getting the nickname "How Much", a pun on her surname (お幾ら, o-ikura) and a reference to her personality.