ベルトワーズ・ベツィー

Betsy Beltoise is a supporting character in the series. She is the vice president of Shuchiin Academy's sister school in France. She is a highly skilled debater, and is known as "The Wound-licking Razor" who reduces people to tears with her quick wit.

(Source: Kaguya-sama wa Kokurasetai Wikia; edited)