Blue Sea

Biodata

Feature	Information
Name	Blue Sea (青海)
Type	Oceanic planet and homeworld of the Blue Sea peoples
Status	Active; classified among the Third-Class Stars during the final conflict 408
Ruler / Protector	Gaston Figo, the King of the Blue Sea 195 206
Primary Defense Force	Blue Sea Marines / Space Marines 205 206

Power Progression

Stage / Realm / Level	Chapter	Notes
Isolated world	144	Figo describes the Blue Sea as a tiny, unmarked speck in the wider universe, vulnerable if hostile spacefaring forces discover its Devil Fruits and Seastone.
Beginning of modern spaceflight	133 144	Moon Landing One launches for the first Blue Sea moon landing; Figo later publicly initiates the Great Space Age of Navigation.
Emerging stellar power	195	Despite only seventeen years of connection to the Starry Sky, the planet possesses 26 Kings and 93 Flame igniters.
Recognized Third-Class Star	408	The Blue Sea is counted among the Third-Class Stars during the final crisis.

History

Ancient history

The Blue Sea was visited by technologically advanced Moon people roughly 1,100 years before the modern era. They traded technology for gold and helped the Blue Sea nations develop, but eventually departed after gathering sufficient gold. 117 143

A later Space Pirate fleet arrived intending to deliver Devil race-related technology to the Moon people. The Blue Sea nations split over whether to accept the technology, leading to conflict among the Blue Sea peoples, the Moon people, and the Space Pirates. 117

The Amatsuki clan secretly attacked the Space Pirates, causing mutual destruction. The Kozuki and Shimotsuki clan heads exiled the Amatsuki clan, which later established God's Country on the Red Line using seized Space Pirate technology. 117

God's Country conducted human experimentation in an attempt to create the Devil race. Joy Boy, a survivor of those experiments, escaped and later fought against the nation, but was defeated by Im. Im and the Twenty Kings subsequently formed the World Government and concealed the history of Devil Fruits and God's Country. 117

Rediscovery of the Starry Sky

Figo reached the Final Island by tracing the relationship between Sky Island, Fish-Man Island, ancient messages, and abnormal ocean currents. The island was accessible through an abyss where gravity and atmospheric conditions became distorted. 116

At the Final Island, Kuroha translated a monumental record of the Blue Sea's ancient contact with cosmic civilizations. Figo renamed the island Voyage Island, framing it as the beginning of a new journey rather than the end of the sea. 117 118

Figo later released sea charts, including Voyage Island's location, and challenged the people of the Blue Sea to make their world's name known among the stars. This announcement formally opened the Great Space Age of Navigation in Marineford Calendar 1484. 144 206

Blue Sea Defense War

The Devil race invaded the Blue Sea in Marineford Calendar 1501, seeking revenge against Figo for killing Giant Demon Yato and pursuing the Devil Race Liberation Plan. 196

Led by Figo, the Blue Sea's Marines and adventurers defeated the invading Devil race. The victory brought the planet to the attention of the wider Starry Sky and began its rapid rise as an interstellar power. 205 206

Geography

• The Blue Sea is a predominantly oceanic world, with the Red Line Continent visibly dividing its surface from space. 134
• A planetary membrane separates its familiar blue sky, clouds, air, and gravity from the surrounding Starry Sky. 134
• It contains nearly one hundred Sky Islands, most located above the Grand Line. 195
• The Final Island—renamed Voyage Island—lies beneath a sea-level abyss created by converging currents, distorted gravity, and near-vacuum conditions. 116 118
• Its oceans contain exceptionally large Sea Kings, a feature that stood out even to visitors from the Starry Sky. 10 141

Peoples and Inherited Traits

The Blue Sea possesses an unusually high number of races for a world that was isolated from the Starry Sky. Babani considers both its racial diversity and its giant sea beasts abnormal by interstellar standards. 141

Its inhabitants descend from the scattered bloodlines of the thirteen Kings who fought Devil King Lucifer ten thousand years earlier. This inheritance explains the widespread aptitude of Blue Sea powerhouses for Pulse Seeking and Flame cultivation. 258

Known peoples of the Blue Sea include:

• Humans
• Fish-Men and Mermen
• Giants
• Mink
• Sky Islanders
• Wano-descended clans and other regional peoples 95 117 141

Government and Defense

Figo established the Starry Sky Marine Department after the Blue Sea Defense War, preparing the planet to receive external powerhouses and build a formal educational system. 205

For fourteen years after the war, Figo remained on the Blue Sea without leaving, personally deterring hostile outsiders while the Space Marines defended allied worlds. 206

By Marineford Calendar 1515, the Blue Sea had established diplomatic relations with 714 life-bearing planets in the East Universe Sea. Of those, 243 accepted Blue Sea protection and received Space Marine branches. 206

The Blue Sea maintains a severe stance toward piracy and criminal activity; this policy was noted favorably by visiting Starry Sky Mink. 141

Relationships

• Gaston Figo — King, chief protector, and architect of the Blue Sea's modern expansion into the Starry Sky. 144 205 206
• Blue Sea Marines — The planet's principal military and law-enforcement force; expanded into the Space Marines after the Defense War. 205 206
• Zou Star Mink race — The first major modern extraterrestrial contact after the Blue Sea's moon landing. 133 141
• Devil race — Historical source of Devil Fruit technology and a recurring hostile force; their invasion was defeated in the Blue Sea Defense War. 117 196 205
• Celestial Dragon Star civilization — Connected to the ancient history of Devil race conflict and later became a major external power affecting the Blue Sea. 117 258
• Voyage Island — The Blue Sea's former “Final Island,” renamed by Figo as a symbol of interstellar exploration. 118 144