Shinpei returns to his home island to attend the funeral of his childhood friend, Ushio, who died accidentally at sea. He quickly realizes that something is wrong... Some people act strangely. And if it was an accidental death, why was an autopsy of Ushio's body ordered? But before he can truly investigate, Shinpei is murdered by an Ushio lookalike. And now he wakes up on the boat that takes him to the island to attend Ushio's funeral...! He seems to have gone back in time... Will he manage to understand what is happening and stop it before it is too late?