Dreamscape

The Dreamscape is a mysterious plane of existence separate from the Afterlife where certain people who have died seemingly live on, and where certain people can visit in their dreams. So far, only The Conductors and Yui Amaya are known to inhabit or frequently visit the realm, though Yuzuki Tokai has also visited, much to Yui's reluctance, and possibly Anisa Nobunaga, though it's possible she was simply met through an ordinary dream of Yui's.