Ever since he was young, Ai had an inkling of an elusive being's presence. While exploring another realm, he meets a young girl named Suzuro who remarkably resembles his mother. In a startling revelation, Ai learns that Suzuro is his biological sibling and that he was inadvertently switched with her at birth across parallel universes. This truth leaves Ai with a tough choice to make. Experience the narrative of two individuals intricately linked by a fateful turn of events.