Sayonara, Hero. Manga

Sayonara, Hero. summary:

When a boy she doesn't know confesses to her, Yoshinaga finds herself the victim of bullying at the hands of his girlfriend and her female classmates. She resolves to endure it alone, until a classmate stands up to the bullies and sweeps her off her feet (literally!). The closer they get, the more she comes to care for him... but little does she know, her hero is hiding a sad secret of his own. (from shoujo-sense)