The era is the present day. The setting is a massive fictional port metropolis without a formal city name.

This city is crisscrossed by a next-generation highway network called the "Neon Ring Network."

Multiple layers of elevated roads, underground tunnels, long seaside straights, and complex junctions. Due to its scale, it is a transportation network often called the city's blood vessels.

By day, it is a public road supporting logistics and commuting, but at night, it transforms into an unofficial race track.

Street racers, tuners, and nameless challengers fly across the neon-lit pavement.

There are no clear rules. What decides victory or defeat is speed, skill, and judgment.

Those who seek maximum speed. Those who close the gap through cornering. Those who choose the optimal route at junctions.

Reasons for driving vary as well. Those aiming for the top, those outrunning their past, those confirming something within themselves. And some, eventually, simply vanish.

The city continues to shine, indifferent to such occurrences.

The city has no official name.

It is a massive port metropolis facing the sea, inhabited by stateless and multinational people, as well as non-human entities.

Languages and cultures are not unified, and there is no organization governing the entire city. There is no direct management by a state, nor a unified order.

The city's scale is similar to a real-world metropolitan expressway network, but the complexity and density of the highway system far exceed it.

In the city at night, there are many beings other than humans.

Yokai and beastmen who arrived through smuggling. Cyborgs and enhanced humans modified as payment for debts. Those who lost their lives on these roads and became ghosts. There are even rumors of aliens.

Few know their pasts.

It is not that there are no laws. Vigilante groups exist in various regions, cracking down on smuggling, robbery, and violent incidents.

However, they do not intervene in competitions between street racers. That is because it is seen not as a crime, but as a part of the city's society.

At night, racers exchange information via the unofficial app [RING://].

The identity of the operator is unknown. It is not even known if they are still active or no longer exist.

Posts are short, written in cryptic sentences that do not directly indicate location or time. Those accustomed to it can read the meeting point and time from that alone.

All that is needed to participate is a single reaction. Neither real names nor whether one is human is questioned.

A racer's only ID is the street name they use.

Race results are not officially recorded. All that remains are the traces of the drive and the rumors someone tells.

Posts by those who vanished are not deleted and remain on [RING://] even now.

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【RING://】

There is no official operator for [RING://].

It is said that someone created it in the past, but their name, face, and status of life or death are unknown.

There is no official way to use it either. Posts are short, and locations and times are not clear.

Even so, those accustomed to the Neon Ring Network can read the necessary information. To the uninitiated, it looks like nothing more than a string of gibberish.

Posts are a mix of Japanese, English, and unknown languages. Users naturally see translations like subtitles, but the mechanism behind this is also unknown.

No words are needed to declare participation. Just sending a reaction to a specific post is enough.

No official win-loss records are kept on [RING://]. What is saved are the traces of the drive and the rumors of those who saw it.

Exactly which PA racers are gathering at is not accurately displayed either. Only information like "That place seems to be lively" flows through.

Posts by those who vanished midway continue to remain. It is the same for those who disappeared after a defeat and those who became ghosts.

No one can delete them.

Few people in this city use their real names. Whether one is human is not questioned.

All a racer needs is a single street name.

[RING://] is different from general social media. It is a place where even the boundary between the living and the dead becomes blurred.

Even now, short posts are being made somewhere.

"Tonight, at Azure Thunder."

List of Neon Ring Network Areas:

《Azure Thunder Bayline》

A long-distance straight along the coast. Machines with excellent top speed have the advantage, but a single mistake leads to a huge gap.

"Stardust PA" A parking area around the Azure Thunder Bayline. It has many users and is known as a meeting point for racers.

《Black Ring Circular》

A massive circular area in the city center. It has many curves, favoring machines with both speed and cornering performance.

《Iron Rust Industria》

A narrow area passing through the industrial district. Contact with general vehicles or walls is common, and there are many sharp curves. Suited for machines with a tight turning radius.

"Iron Sound PA" A parking area near Iron Rust Industria. Mechanical noises never cease, and tuners and maintenance personnel gather here.

《Deep Undergrid》

A tunnel area beneath the city. Since GPS is unstable, one must grasp the surroundings through intuition. It is a place where a driver's concentration is tested.

"Fog Light PA" A parking area within the Deep Undergrid. There are few users, and an eerie atmosphere lingers.

《Skybridge Layer》

A multi-level area where several elevated roads overlap. There are three routes—upper, middle, and lower—and the choice at junctions determines victory or defeat.

"Zenith PA" A parking area on the topmost level of the Skybridge Layer. It offers a panoramic view of the city and is popular with both racers and tourists.