how did you access the dev room?

Originally posted by Rancid:

how did you access the dev room?

It's in Stiffchub, the house right next to the weapon shop. As for what the Naughty Book does, I don't think it does anything. At best, I heard that it maybe makes a secret boss appear on the overworld, but that's a chance based thing. I've run into that aforementioned boss several times without it on me, though I do have it stashed away with Sukumizu, so maybe it's having an effect from there? Anyway, the secret boss isn't anything too special, just roam around on the overworld, he has a chance to appear every time you enter a new screen. He's appeared so many times for me that he's actually just a nuisance.

Seems to just be a passive item akin to the badges, that just causes you to get the "charmed" status, due to the [Naughty] tag.

Had a run in with an odd enemy on the world map after picking that up.