Houdzuki Maika is a high school girl who, in a sense, is never alone.
Her twin brother Maito, who could not survive birth, lives inside of her
and shares her body. They switch between who gets to live each day and
they share most of their memories. However, the only times they get to
see and talk to each other is when they are both asleep, where they
share the same dream. Perhaps as a result of this supernatural
existence, they have the ability to see ghosts. These twins will surely
face many mysterious events ahead!