Sorji and Keno VS. 4 weird pirates

Prologue
A little boy runs to Sorji. "Could you please help me? My grandmother is getting attacked by bad men!"

Battle
Volume 1, Chapter 5 They fight (it only takes ~1 minute).

Aftermath
Sorji and Keno have got some money and made the UDC - their own pirate crew. And the grandma's saved.