Aho-girl: A Clueless Girl 12 by Hiroyuki
Yoshiko is a hopefully clueless high school girl. Her rock-paper-scissors strategy is rock. She somehow gets zeroes on multiple-choice tests. And she has an often-nearly-fatal weakness for bananas. Her devoted friends have no choice but to hang around and make sure nobody takes advantage of her. (Of course, the entertainment value might have something to do with it, too.) Cute characters, weird gags, and lots and lots of bananas!