The Red Line's origins in One Piece may be much simpler than fans think

The Red Line in One Piece has always been mysterious. The size, shape, and consistency of the Red Line confuse even dedicated fans—but perhaps the explanation isn't so complex. Some believe it mimics Earth's Ring of Fire. This volcanic ring follows tectonic boundaries, and perhaps the same holds in One Piece. Volcanic natural chains could provide its foundation.

The World Government may have only enhanced it. The Magu Magu no Mi could've sealed its structure, and together, nature and power created this giant wall. If true, it means the Red Line wasn’t entirely man-made; it was simply reshaped and weaponized. That makes the Red Line’s origin more grounded than fans expect.

Disclaimer: The article reflects the writer's opinion and includes spoilers from the One Piece manga.

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How the Red Line's origins in One Piece may be much simpler than fans think, explained

Red Line as seen in anime (Image via Toei Animation)

The origins of the Red Line in One Piece might not be as complicated as most fans think. Instead of being entirely artificial, it might be something more natural. One theory suggests that the Red Line is based on the Ring of Fire from the real world. This Ring of Fire is an enormous volcanic belt surrounding the Pacific Ocean.

It accounts for about 75% of the volcanic activity in the world. It even includes nations such as Japan, which is famous for its powerful volcanic presence. The Ring of Fire is a nearly continuous line, which might be the Red Line's real-world basis.

This theory mainly emerged from chapters 606 and 607 of the manga. In these chapters, the Straw Hats are headed toward Fishman Island. Fans see that the underwater area beside the Red Line is heavily volcanic.

Underwater Volcanoes as seen in anime (Image via Toei Animation)

Massive underwater volcanoes erupt as the crew travels through this region. This fact seems too significant to be coincidental. The fact that there is a volcanic belt on the path of the Red Line mirrors Earth's Ring of Fire almost perfectly.

The Ring of Fire hypothesis also accounts for other volcanic islands existing in One Piece. Little Garden and Punk Hazard are two prime examples. Both islands feature prominent volcanoes and are relatively close to the Red Line.

While most of the Ring of Fire’s volcanoes are underwater, plenty are on land. This supports the idea that the Red Line could be a global volcanic belt. It’s just been misunderstood as something entirely artificial.

Volcanoes at Punk Hazard (Image via Toei Animation)

Volcanoes are not just destructive; they are also creative forces. Many real-world islands were born from cooled lava. One Piece chapter 156 mentions land formed by volcanic activity.

If this world’s Ring of Fire truly exists, it could have built the Red Line over time. However, the idea goes further than that. Someone may have sped up the process using one of the strongest powers in One Piece—the Magu Magu no Mi.

Akainu as seen in anime (Image via Toei Animation)

This Devil Fruit is the second tool in the theory. Its power is simple but deadly: magma. Akainu or Sakazuki, the current Fleet Admiral, employs it to destructive ends. With him, magma is a mass destruction weapon. Like Meteor Volcano, his ability pours molten fists down from the heavens.

Great Eruption illustrates the magnitude of devastation he can create. If someone had had this power long ago, they could have manipulated volcanic belts. They wouldn’t even need to create anything from scratch. They’d only need to trigger eruptions in a chain reaction.

The Red Line as seen in anime (Image via Toei Animation)

Picture a massive belt of volcanoes circling the world. Most are underwater, some on land. If they are close enough, a user of the Magu Magu no Mi could trigger them one after another.

The result would be a massive, continuous flow of magma. Over time, this lava would cool, harden, and stretch across the planet. That would form the Red Line—a giant natural wall powered by nature and shaped by Devil Fruit abilities.

This would also explain the scars seen on the Island Whales. The Red Line blocked these massive creatures and left them with deep marks. It hints that the Red Line wasn’t always there. It was built—perhaps violently.

Island Whale Laboon (Image via Toei Animation)

The World Government may have used natural tools to assert control. In place of pure technology or magic, they employed volcanoes and an energetic magma user.

Lastly, there’s real-world inspiration to consider, and Japan's Oki Islands provide an excellent example. This cliff is strikingly red and was shaped by volcanic eruptions. The red hue is due to oxidized minerals in the volcanic rock.

There are numerous such examples in Japan since it lies in the Ring of Fire. Eiichiro Oda might have been inspired by this natural landmark when conceptualizing the Red Line. The similarity in color, form, and cause is difficult to overlook.

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Final thoughts

The Ring of Fire (Image via EVL UIC)

In One Piece, the Red Line's origin might be more geological than fantasy. Chapters 606 and 607, depicting volcanic activity off Fishman Island, lend serious credence to this theory. Islands such as Punk Hazard and Little Garden support the notion of a volcanic belt.

The Magu Magu no Mi, used by Sakazuki, might have caused eruptions to form the line. The Island Whales' scars suggest a violent origin. Real-world inspiration, such as Japan's red cliffs, supports this. Oda may have simply mixed nature and power to create the Red Line's actual origin.

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