TOO MUCH FANSERVICE NOT ENOUGH PLOT
They're on an island oasis wearing (barely legal?) swimsuits and the girls are hallucinating and started to do yuri stuff because of the fish the gun nut (Hirano) caught.
that's pretty much the entire plot right there...
I feel guilty watching this 16 minute drivel, if it weren't for the fanservice I would've given it an even lower score.
I love how you admit you just continued watching it for the fan service.