Two days before her fourteenth birthday, Ashley Mizuki Robbins receives a package from her father, Richard Robbins — a man she believed was dead. Inside is a small handheld device called a Dual Another System ("DAS," renamed the Dual Trace System or DTS in the American release), along with an invitation to meet him on Blood Edward Island. The next day, Ashley and her aunt Jessica Robbins travel there.
On the island, Ashley meets "D," a memory-less ghost who has wandered alone for decades since his death. As she works to help D recover his lost memories, she also digs into the truth about her father, a murder, and a mysterious initiative code-named "Another."