Umineko no Naku Koro ni Theories

During it's run, there were many fan theories attempting to find the solution to the mysteries of Umineko no Naku Koro ni. Listed below are some of the most popular of those theories.

Shkanon

The Shkanon theory postulates that Shannon and Kanon are either the same person or are simply working together to commit the murders on Rokkenjima. This was proven correct with the existence of Sayo Yasuda.

Rosatrice

The Rosatrice theory is an alternative explanation of the murders on Rokkenjima in which Rosa Ushiromiya is the mastermind with George Ushiromiya and Doctor Nanjo as her primary accomplices.

Small Bombs

The Small Bombs theory was postulated by Battler Ushiromiya in Turn of the Golden Witch. Battler suggests that the first twilight, wherein the victims were found with their intestines ripped out sitting around a Halloween party table, was a result of the culprit feeding the victims "small bombs" in their meals. The absurdity of the theory has led it to be a subject of ridicule with fans.

Clumsy Gohda

Until we reach the Golden Land

A rather humorous theory postulating that Toshiro Gohda was involved in every murder on Rokkenjima, committing them accidentally through a series of mishaps. This theory also makes use of the Small Bombs theory above, claiming Gohda accidentally used a box of "Tiny Food Bombs" instead of sugar while preparing snacks for the Halloween party. When Battler Ushiromiya learns the "truth" of the murders, he finds it too ridiculous to believe and instead decides that it is more likely that a witch did it.

Bernkastel's true identity

It has long been speculated that Bernkastel is the same character who wrote the poems introducing each chapter of Higurashi no Naku Koro ni. A very popular theory is that this same Bernkastel is actually Rika Furude, a theory supported by both characters having fragment-hopping abilities as well as similar appearances. This has been confirmed by Ryukishi07.

Lambdadelta's true identity

Lambdadelta is Bernkastel's companion voyager witch and thus is the subject of speculation regarding a possible human identity. The most common version of this theory is that Lambdadelta is Miyo Takano, main antagonist of Higurashi no Naku Koro ni and Rika's main rival. This is supported by the similar hair between the two characters. Another common speculation is that Lambdadelta is Satoko Houjou, Rika's best friend. This is supported by similar hair colors between the two as well as the similarity of Rika and Satoko's relationship to Bernkastel and Lambdadelta's relationship. Ryukishi07 has dismissed both theories as red herrings.