Comedy Island: Japan S01E02 - Box

On their second day on the island, the comedians are tested by the groom as well as his father who distrusts them. Half of the comedians go to help an islander whose husband has been missing since the night before. While trying to pass the unexpected challenges with improvisations, the comedians encounter one of the ruins of laughter on the island called "Wataful". What on earth is "Wataful"?