The main plot-hole for me is - indeed - the over one hour interval that is never accounted for. It's probably not too hard to fix by tweaking the timing a bit, making the tournament start earlier, say that it was dark and it took a while for Diana to even realize Wolfgang was there, etc.
There were a few instances in the plot that weren't plot-holes per se, just stuff that gave me this feeling of... "These characters have really weird thought processes". Like... the blackmails. Both Toshiko's and Cassidy's are laughable nothing-burgers, right. Tozu himself confesses he was having a hard time finding material and had to wing it. So, in that context, Damon looks at the cryptic one he received about Wolfgang - stuff that looks more like subjective opinion than fact either way - and goes "Oh my, this has got to be important, I should contact my psychopathic kidnapper and ask him to break the rules of his game and give me privileged information!" This might speak more to the sort of person Damon is, though.
Second one, when he's discussing Desmond's with Eva. Again, cryptic shit. Is this "one he trusts" they are talking about a person, an object? Assuming it's a person, is that person here, in Eden Garden? Because these are supposed to be about their lives outside of Eden's Garden, right? But no. Eva jumps to the conclusion Desmond has an entire armory in his dorm, from that vague statement. I don't think the statement supports that conclusion, but on that same token... are you telling me the ULTIMATE MARKSMAN who walks around with a QUIVER FULL OF ARROWS and brags about being proficient with multiple accuracy devices, and has a room themed around his talent here... HAS WEAPONS??? Shocking. But wait. You know what I have NEVER heard being used in target practice competitions? Tasers.
These are relatively minor issues though. 5 chapters of this level of quality, artwork, music, voice acting, scope, I'd be selling for $60 on Steam. I'm not exaggerating.