Yotsuba (四葉 Yotsuba?) is a minor character in Toaru Majutsu no Index mentioned in Volume 1. When Kamijou Touma hurriedly calls Tsukuyomi Komoe to ask her about "Mind Hound-related matters" (memory manipulation), Komoe recommends calling in a guest esper who specializes in that field. Komoe then points out Yotsuba, who she describes as a Level 4 esper of the Telepath category that is also a member of Judgment.