2061 AD. Fifty years have passed since mankind developed the Network society. It was anticipated that this new infrastructure would realize a utopia where people connected with each other at the level of consciousness. However, new social problems such as personal data leaks and proliferation of manipulated information began to surface. Nevertheless, people still relied on the Network to exchange information, and proved unable to opt to abandon it.
In due course, a new Network realm with more effective security measures was developed. This was called Meta Real Network, usually abbreviated as "the Metal."
The Metal accommodated personal memory data within protected virtual stand-alone organic cyber enclaves called bubble shells and eventually pervaded the everyday lives of people.
However, people gradually learned to release and explode their instincts within the secure environment of the Metal. The unleashed instincts pushed each individual's consciousness to drown in the sea of information and to be exposed to the pressures of desire. Meanwhile, norms and regulations continued to bind their real world lives. Thus, strange friction between the two worlds began to manifest themselves as aberrations beyond the bounds of the imaginable.
Experts who challenged the deep sea of the Metal to investigate and decipher such aberrations were called cyber divers.
This is a story of a cyber diver, Masamichi Haru, who investigates the incidents that lie between Reality and the Metal.
(Source: Production I.G)
Construction of an artificial island is disrupted by an unexplained phenomenon known as "burning sea". Masamichi Haru is injured by burning sea during a test of early Meta-Real technology, leaving him comatose for fifty years. Now elderly and wheelchair-bound, he still hopes to solve the mystery of burning sea. His friend Eichiro Kushima now hopes to use the Meta-Real, also known as the Metal, to research the burning sea phenomenon.
Aoi Minamo is hired to be Haru's assistant. When burning sea causes a power outage that threatens life support systems on the artificial island, Minamo rushes to the electrical substation, while Haru uses his cyberbrain to dive into the Metal Network.
Haru has become an official investigator and is asked to dive into the Metal to rescue the consciousness of an Artificial Island shareholder who has experienced braindown.
Minamo searches for a pair of antique Sous-Marin sunglasses as a gift to congratulate Haru on becoming an official investigator. During the search, Minamo and Sota have a run-in with champion fighter Iron Schwartz.
Because of her lack of a cyberbrain to read online texts, Minamo must find a physical book for a book report. Her discovery reveals the true story of a lost love.
Minamo and Haru discover a dog whose consciousness was swapped with that of his owner. They hurry to find the owner's body before it becomes too late for them to switch them back.
Those who contact a mysterious oracle in the Metal named Eliza end up with lost memories. During the investigation, Minamo realizes that Haru has been talking to none other than Eliza.
Minamo meets Amy, a girl who has just received cybernetic eyes to cure her blindness, but learns that Amy is struggling to adjust to being able to see. Meanwhile, Haru is asked to investigate the disappearance of a highly sought-after artist in the Metal.
Haru reminisces about his youth, from his parents' struggles with poverty that led to trouble with the yakuza, to his meeting a dolphin that inspired his fascination with the sea, and finally to his exploration of the ruins of his city, now underwater because of climate change, which led him to become a test diver for early Meta-Real experiments.
Haru, Minamo, Sota, and Holon go to a distant jungle island to investigate a mysterious background noise in the Metal. All seems well until ionization in the rainforest disrupts Holon's cyberbrain.
At the jungle island, Haru realized that he can learn to walk again, and he begins to practice in secret to avoid jeopardizing his job as a Metal diver. Meanwhile, Minamo gets tested for suitability to receive a cyberbrain.
