Suu Hifumi (一ひ二ふ三み 数すう, Hifumi Sū?), is a character in The 100 Girlfriends Who Really, Really, Really, Really, Really Love You. She is Rentarou's 23rd girlfriend, a third-year student at Ohananomitsu High School, in class 1-3. Suu is obsessed with numbers, to the point of declaring that she is romantically in love with them, seeing them as unique, sentient beings. As a child, she even wanted to become numbers, and tried doing so by posturing her body to resemble them. Due to her love for numbers, she is bad at basic mathematics, and dislikes most other things that are not numbers (even Rentarou, at first). Rentarou wins Suu over by posturing his body to resemble numbers, and telling her that together, they can make any number they wish.