The protagonist of the anime One-Punch Man Saitama made a name for himself that can beat every one with a single punch.
Is there any anime character who can challenge him? We made a small list of characters who can do that.

1. Kurosaki Ichigo (Bleach)

Kurosaki Ichigo (Bleach)

Even if ichigo don't seems to have to have a chance against saitama, you can't be so sure about this.

Because what we learned of ichigo that he never ever give up, with his hollow form and the hollow ichigo the quincy power and more he can give saitama a really hard time.

2. Sosuke Aizen (Bleach)

Sosuke Aizen (Bleach)

Aizen is feared in his own series and even in other series, he is also ranked to be the villain of villain's.

And with his many and many kido's he might beat saitama even without a zampakto.