Chapter 13

Hammerhead orders his followers to rush Speed-o'-Sound Sonic and can only watch as the ninja beheads every one of them, barely dodging death himself. He slams the earth to send out a huge shock wave, but it does nothing to Sonic, who mocks him from a nearby tree. Now aware of his target's spot, Hammerhead hurls a massive boulder, which Sonic slips aside from; the rock sails on to crash through the roof of Zeniru's tower. As Sonic touches down, a second boulder narrowly misses his landing point, and he weaves through a whole volley of them without a scratch.

Hammerhead then bursts through several trees to taunt his foe, but Sonic realizes the scattered boulders have carved a clean, direct lane running straight from himself to Hammerhead. When Hammerhead hoists another rock and jeers again, Sonic drops into a stance and charges. Hammerhead lets the rock fall, tears up a tree, and slams it down along that path, only to take a kunai to the back of the head from Sonic, who had already slipped behind him. Sonic pulls out his phone to tell Zeniru the job is done, then looks back to find Hammerhead vanished. His thick skull having spared him, Hammerhead flees through the woods until he stumbles upon Saitama.

Sonic slaughters Hammerhead's gang and shrugs off his shock wave and thrown boulders, then baits him into a straight charge and drives a kunai into the back of his skull. Believing him dead, Sonic reports to Zeniru, but Hammerhead survives thanks to his hard head and flees, running right into Saitama.

This chapter belongs to the Paradise Group Arc and appears in Volume 2, released on September 5, 2012 and corresponding to webcomic chapter 13. Its events are adapted in Episode 4 of the anime, and Speed-o'-Sound Sonic is the cover character. King and Charanko slip in for a cameo before their formal debut; notably, the online release had Charanko cry out during that moment, while the volume version reassigned the scream to King.