I wonder if it's okay to ask this.
Well I know it's kinda hard to find this manga, but I apparently found a completed version. It has 4 large chapters and 1 ten page chapter, a total of five. I also found a 31 page extra in a different site entitled ''extra 2''.
The thing is, Myanimelist says it has a total of 6 chapters, but what I have looks more like 4 chapters and two extras. Is it complete? Are they counting the extra as a chapter? Or am I still missing one chapter? This is so confusing.

My guess is that they're counting the extras as chapters 5 and 6. Where did you find those extras??