Mercenary Pursuit

Story

"The Astin Mercenaries betrayed us, nyerk!"

With Kochi's whereabouts still unknown, Arin provided information about a band of mercenaries causing trouble at the Southern Shugo Station.
It turns out they are the Astin Mercenaries, a group known to have previously worked with Kochi, and infamous in the region for their nasty behavior.
You immediately entered battle after witnessing the Astin Mercenaries attacking the Southern Shugo Station.
Though nothing was learned about Kochi, you captured and interrogated a mercenary. In addition to Astin's current location, the mercenary revealed that Astin held no goodwill toward the Shugo despite his contract with Kochi.

Completion

Talk to Astin at the Astin Mercenaries Base