"The Promise Girl is Keitaro's Childhood friend who he can't remember either the name or the face of, but they made a promise 15 years ago to get into the Tokyo University (Todai) together when they grew up. She is the sole driving force for Keitaro's determination to pass the entrance exam and be admitted to Tokyo University. Her identity is a mystery until late in the manga, while her identity in the anime is still in ambiguity."@en . . . . "Promise Girl"@en . . "The Promise Girl is Keitaro's Childhood friend who he can't remember either the name or the face of, but they made a promise 15 years ago to get into the Tokyo University (Todai) together when they grew up. She is the sole driving force for Keitaro's determination to pass the entrance exam and be admitted to Tokyo University. Her identity is a mystery until late in the manga, while her identity in the anime is still in ambiguity."@en .