Danmachi is a semi-alright series, with some flaws, and a fuck load of tits; the OVA after the first season of Danmachi is acceptable... but this... this isn't it chief. This isn't a good example, now, I don't write reviews. I put my consensus on the notes part of my anime list, not write a full on 500+ character review about an anime series (or OVA).
I like beach episodes and OVAs in an anime as much as the other guy, and when I found out that this OVA was a thing. At first glance, I thought "Well, considering there's a new character who is literally a kitsune prostitute thing. There will not just be tits galore because it's on a beach and bikinis are a thing, but I guess there will be some like element of seduction."; but not outright stupidity from pretty much every character.
I have no clue how I watched all the way through that, but that was the worst OVA ever. Do not watch this OVA at all costs, even if you're a Danmachi super fan, do not watch it. You will hate it. I thank god every night that this is not canon to the series, because if it was. Season 3 would not be on my radar and I would avoid that shit at all costs.
Now, I do not like saying the word "cringe", but this is literally cringe. The jokes are cringe, I didn't laugh at it. If anything, just them constantly saying "Barbeque!" or "Ew, it's a Sea Cucumber, gross!" over and over again enrages me.
Just to reiterate:
Do not watch this.