A promotional video celebrating the milestone of 600 million copies sold worldwide for One Piece introduced an unusual idea: the truth behind the series was written down by creator Eiichiro Oda and sealed inside a container, then placed deep beneath the ocean floor.
According to the video’s description, the document containing the truth will remain hidden until the story concludes, at which point it will be publicly revealed. The footage shows the preparation, deployment, and descent of a pressure-resistant capsule carrying the secret.
For most viewers, the moment served as a symbolic marketing gesture. But one fan decided to approach the video like a puzzle and began investigating whether the drop location could be identified using the clues shown on screen.
After analyzing timestamps, maps, ocean depth data, weather conditions, and geographic features visible in the footage, the investigation proposes a specific real-world location where the capsule may now rest: Toyama Bay, near Japan’s Noto Peninsula.
The starting point for the investigation was gathering all the factual information presented in the video itself. Several timestamps reveal the sequence of events surrounding the capsule’s deployment.
Ship in the YouTube Video
At 0:09 in the video, a caption states that the footage begins on February 8, 2026, at 1:25 PM inside Eiichiro Oda’s studio. Later, at 0:57, another timestamp notes February 12 at 2:38 PM, when the chest containing the secret document is sealed inside a pressure-resistant glass sphere.
The next critical moment appears at 1:13, where the capsule arrives at a designated drop point at 3:40 PM local time. At 1:19, the deep-sea descent begins at 4:32 PM.
Shortly afterward, the One Piece video indicates the capsule has passed a depth of 200 meters at 4:51 PM. Finally, at 1:32, the probe reaches the seafloor at a depth of 651 meters at 5:04 PM.
These timestamps reveal that the descent lasted approximately 32 minutes. That detail later became useful for estimating the probe’s movement through water.
Another clue comes from a stylized map briefly shown in the video. At first glance, the map appears decorative, but when the frames are combined, they form a recognizable coastline outline.
Map Frames in the YouTube Video
The investigator extracted the fragments and merged them into a single composite map. To make the shapes easier to compare with real geography, the map was redrawn in vector form to capture its contours more precisely.
With the reconstructed map in hand, the next step was to search for matching coastal regions in Japan. Several criteria helped narrow the possibilities.
The coastline had to match the map’s shape, and the drop point needed to be near a harbor capable of hosting research vessels. The seafloor also had to descend quickly to depths greater than 600 meters, relatively close to shore.
Vector Drawn
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In addition, the ship footage revealed almost no visible mountains or large landforms on the horizon, meaning the filming location likely faced open water.
Lighting and shadows in the video also provided an important directional clue. The ship’s shadows extend toward the north or northeast, indicating that the vessel was oriented westward during filming.
After comparing several potential candidates, one location emerged as the most consistent with all these constraints: Toyama Bay along the coast of the Noto Peninsula in central Japan.
Toyama Bay has a distinctive underwater geography that fits the depth requirement extremely well. Often referred to as a “natural fish tank,” the bay features a steep underwater slope where the seabed drops quickly from the shoreline into the Toyama Trough.
Map Locations
In many places, the depth plunges to between 1,000 and 1,200 meters, not far from land. A depth of 651 meters, exactly the value shown in the video, occurs along the upper slope of this trough.
The direction of sunlight seen in the ship footage also aligns with this region. If the vessel was facing west, the camera would have been looking toward the area around the city of Nanao across Toyama Bay. That orientation matches the shadow patterns visible in the video.
One puzzling detail in the footage is the absence of a visible shoreline, even though the Noto Peninsula would only be around 12 kilometers away from a potential drop site.
However, seasonal atmospheric conditions may explain this. In February, the Sea of Japan often experiences temperature inversions where warming air sits above colder seawater. This difference in temperature can create a layer of atmospheric haze near the surface, obscuring distant land even when it is relatively close.
Weather data and satellite imagery further support this scenario. Based on conditions shown in the video, the investigation suggests that the capsule drop most likely occurred on either February 13 or February 19.
Sattelite Imagery
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Both days had partially cloudy skies capable of producing the dramatic sun rays visible in the footage. February 13 appears slightly more favorable, as temperatures briefly reached around 10°C during the afternoon, increasing the likelihood of haze and atmospheric effects.
The Sun
Practical considerations also strengthen the Toyama Bay hypothesis. Following the 2024 Noto Peninsula earthquake, the region became the focus of extensive marine research.
The Japan Agency for Marine-Earth Science and Technology (JAMSTEC) has been involved in ongoing efforts to map and study the seafloor in the area.
With research vessels and deep-sea equipment already operating nearby, it would have been easier for a film crew to collaborate with existing infrastructure rather than organize a separate expedition.
The investigation also examined the physics of the capsule’s descent. Since the probe traveled 651 meters over approximately 1,920 seconds (32 minutes), its average velocity was around 0.34 meters per second.
Using simplified drag calculations that account for seawater density, about 1,027 kilograms per cubic meter during winter in the Sea of Japan, the probe’s effective underwater weight can be estimated.
Assuming a drag coefficient near 1 and a surface area of roughly 0.4 square meters, the calculated net downward force suggests the probe’s effective weight in water was about 15 kilograms.
The total mass of the system in air would likely have been much higher, possibly around 80 kilograms, when accounting for the entire capsule and its equipment.
If the Toyama Bay theory is correct, the capsule now rests on the upper slope of the Toyama Trough, likely positioned on a stable ledge away from high-sediment channels formed by underwater currents. At a depth of 651 meters, the container lies far beyond the reach of recreational diving and would require specialized remotely operated vehicles or submersibles to retrieve.
Interestingly, the investigator also noticed a curious pattern in the comments under the official video. Mentions of Toyama Bay reportedly disappeared soon after being posted, while guesses pointing to other locations, such as Sagami Bay or Suruga Bay, remained visible.
While this could simply be a coincidence, treasure-hunt-style marketing campaigns sometimes remove correct guesses to preserve the mystery.
Of course, the theory remains speculative. Without confirmation from the creator, the exact location of the capsule cannot be known with certainty.
Still, the combination of map reconstruction, coastline comparison, ocean depth analysis, lighting direction, weather patterns, and logistical considerations makes Toyama Bay one of the strongest candidates.
If the One Piece promotional video is to be taken literally, the sealed document containing the truth behind One Piece will remain hidden on the ocean floor until the story reaches its conclusion.
Until that day arrives, the capsule may continue resting hundreds of meters below the surface quietly, holding what could be the most inaccessible spoiler in manga history.
