OVA 3

The Ninja Who is Too Complicated (こじれすぎる忍者, Kojire-sugiru Ninja) is the fourth OVA of the One-Punch Man anime series.

Summary
After the events of episode 4, Sonic finds himself troubled that he cannot fight properly after his defeat at the hands of Saitama. Training in a forest with a Matagi who is looking to kill a bear that scarred him, Sonic rescues a baby boar from a snake that quickly bonds with him. Naming the boar Ino, Sonic continues training, gradually regains his confidence, and eventually leaves the Matagi and Ino, ready to fight Saitama again. Suddenly, the bear who scarred the Matagi (whose name is Frank) appears, only for Saitama to show up (he had previously heard of an influx of bears in the forest, and was hoping to have bear meat for dinner). Sonic silently watches over the city, ready for his next battle with Saitama, while Frank and Ino look with amazement at the forest cleared with a single punch.

Characters in order of appearance

 * Speed-o'-Sound Sonic
 * Frank
 * Ino
 * Saitama
 * Genos