"I (the term 'boku' is used, indicating that the narrator is a male teenager) love math. Just after the high school entrance ceremony I meet a beautiful girl, Milka. Milka is a mathematical genius. She gives me many math problems and shows me many elegant solutions. Milka and I spend a long time discussing math in the school library. A year later I meet another mathematical girl, Tetra. Tetra is one year younger than me, and asks me to teach her math. While I teach her, she begins to understand math and to love its elegance gradually."