The current release has 13 chapters. There are main numbered chapters from Chapter 1 to Chapter 8 (counting both versions of Chapter 7’s route split), plus two noncombat Interludes and two optional Gaiden chapters.
How do you recruit
Explanation
You recruit Bungus in Chapter 3 by talking to him as an enemy with Akira or Brynne. There are no other requirements for that recruitment; the only thing changed by whether or not you fight him in Chapter 1 is a couple lines of dialogue in that chapter’s outro scene.