So there's a guy that's also a martial arts champion (judo, karate?) and because of that everyone avoids him. There's some event and there's this girl who talks to him and thinks he's a nice guy. But because of that the girl gets shunned as well and the guy does something bad to protect her reputation. They avoid each other. Later the girl goes into a forest with some other guy, and the main guy hears there's a bear in that forest. He rushes in only to find the bear beaten by the girl, as she's the aikido champion. They reconcile and end up together. Girl is classic shoujo heroine, the "kyaaa" light-haired bunny while guy is also classic, cool black-haired loner. The art style is what you can mostly find in this type of genre, big eyes and bishounens. It's not Sumomomo Momomo.