In the future, the world is heavily polluted as the aftermath of a war that used chemical weapons. If a person is overly exposed to this polluted air, they could die within a month: unless they have a "Life Microchip" (LMC) implanted into their body. Because of this, there is a lot of crime surrounding LMC use. Therefore, the government has set up a special team to handle these crimes: The Lifemicrochip Crime Commando (LWC).
Yuuri Mimori, prompted from his childhood friend Ibuki, decides to join the LWC with him. Despite the extreme danger involved as a member of the LWC, Yuuri feels no qualms about it, thinking that as long as Ibuki is there too, he can endure the severity of the job.
On their first day, Yuuri and Ibuki are guided by Roy, the leader of the LWC, to meet the various members of the team that they will have to work with. That night, Yuuri returns to his room, a bit tense from the first day, and begins to lose consciousness. The minute his eyelids started to close, he felt a horrible pain in his chest.
Yuuri has suffered from a terrible illness since he was young. If he does not take medicine regularly, this disease will cause his body to deteriorate. As he starts to lose consciousness, he feels a warmth on his lips, and a voice at the edge of his senses is telling him to hang in there. Something cool passes into his mouth, and when Yuuri begins to return to consciousness, he sees Ibuki's worried facing looking down at him.
Since then, when Yuuri sleeps, he sees the same dream every night, where he feels submerged in water, like a fish, and a voice gently calls out his name from a deep darkness. Whenever he tries to confirm who it is, he wakes. What is the meaning of this dream...?