After orphan Teru Kurebayashi loses her beloved older brother, she finds solace in the messages she exchanges with DAISY, an enigmatic figure who can only be reached through the cell phone her brother left her. Meanwhile, mysterious Tasuku Kurosaki always seems to be around whenever Teru needs help... Could DAISY be a lot closer than Teru thinks?

Teru gets kidnapped, and Kurosaki rushes to find out where she's being held. The search takes him to an uninhabited island where Akira is determined to find "M's Last Testament." With the entire island rigged to blow up, will Kurosaki save both Teru and Akira in time?