/jp/ - Otaku Culture

I didn't come up with this, but it's fairly interesting and I agree with it:

"Rokkenjima sits at the crossing point for multiple parallel universes. Hence why characters can be alive, dead and absent simultaneously, why Kanon gets more screen time as a dead man than alive, how the killer can walk out of a locked room and murders can happen when every every named characer has an alibi. The murder from arc X might have been prepetrated by the murderer from arc X+1. The mutually-contradictory message bottles are remnants of worlds that were 'collapsed' when the typhoon passed. Kinzo knew about the island's 'magical' properties, of course: he's depending on them for his one-in-a-quadrillion miracle to occur. "
This makes sense given what Virgilia explained in EP3. It also makes sense if you recall that the entire umineko/higurashi story takes place in a multiverse. This doesn't explain who the murderer is but it does explain how the game boards are reset with them being alive every game.