On Tamagotchi Planet, Mametchi has just finished his new creation. But on its first trial run, Kuchipatchi manages to throw the machine's aim off course, which results in a child from Earth, Tampopo, being transported to the Tamagotchi Planet.

After Detective Shunsaku Aoshima is promoted to section chief he has the daunting task of dealing with eight cases at the same time, which includes a murder case, bomb threat, and a bus hijacking. Complications also arise between Detective Aoshima and his juniors.

Detective Murakami meets a girl who suffers from memory loss. The girl has special abilities including the ability to talk with the dead. Detective Murakami names her Maki. Detective Murakami and Maki work together to solves a massive murder case involving a mad bomber. Maki's identity is revealed during their investigation.

20 years after his escape from Impel Down, the legendary pirate Shiki, the Golden Lion, reappears causing massive upheaval to the Marines. During his long seclusion, he was able to come up with a scheme to bring the World Government to his knees. On his way to execute the plan, Shiki crosses paths with the Straw Hat Pirates and becomes so impressed with Nami's knowledge of meteorology that he abducts her to forcedly enlist her into his crew. Luffy and the gang end up on a strange land populated with monstrous beasts as they desperately search for Shiki and Nami.