What virtual reality is Splatoon 3: Side Order set in?

Splatoon 3: Side Order is set in a virtual reality called the Memverse.

The Memverse was created by Marina to help recover the memories of Octolings who had been sanitized by the Kamabo Corporation. In Side Order, Agent 8 enters this artificial world after traveling by train toward Inkopolis Square. The virtual environment appears as a pale, ordered version of the Splatoon world, centered on the towering Spire of Order.

The Memverse is not the same place as Inkopolis Plaza, which is the hub world from the first Splatoon, or Deepsea Metro, the underground test facility explored in Splatoon 2: Octo Expansion. Alterna is also different: it is the snowy site of Splatoon 3’s main single-player campaign, Return of the Mammalians.

Inside the Memverse, an artificial intelligence named Order hijacks Marina’s project and tries to impose perfect order on the real world. Agent 8, Pearl, Marina, and Acht must climb the Spire and stop it. The setting’s virtual-reality presentation also explains Side Order’s surreal scenery, grayscale aesthetic, and repeatable roguelite structure.