Fukagawa Drift Containers: Review Board Decides to Open Just One, Under Sealed Conditions — the Other Two to Remain in Storage

Before dawn on Aug. 21, three metal containers washed ashore on a street in Fukagawa 2-chome. On the 16th, the Third Appraisal Center's review board held a closed session in a district meeting room and settled on a decision: only one of the three will be opened, under sealed conditions, while the remaining two stay in indefinite storage for now. The ruling comes 26 days after the containers were found, and four days after a Sept. 12 briefing for local residents.

All three containers are cylindrical, roughly 30 centimeters tall, and filled with a liquid resembling water. As previously reported, the liquid's surface fails to follow the container's tilt even at angles up to 15 degrees, a result confirmed by both X-ray and acoustic measurement. A Sept. 2 working-group report found "no abnormality in the measurement system or image processing" — in the center's words, "the ruler itself is sound" — but could only go so far as to say the behavior was "likely attributable to some property of the object itself." The isotope ratios match none of the 147 known lineages then registered in the world-line matching database, and a slight difference in the engraved lettering across the three containers has left open the possibility that more than one point of origin is involved.

The board had originally planned to treat, for the first time as a formal agenda item, the "leave sealed, keep in storage" option that surfaced in the Sept. 2 working-group report. In Tuesday's session, both that option and a proposal to open at least one container for direct analysis were on the table; the two were eventually merged into a compromise — open one, keep two in storage.

According to the Third Appraisal Center, the container chosen for opening is the one where the non-tilting liquid surface has been most consistently observed. The reasoning, officials said, is that "there's no need to touch the other two, which appear to share the same property" — findings from the opening will instead inform how the remaining two are handled. The opening itself will take place inside a sealed, gas-tight chamber cut off from outside leakage, with the container's internal gas and liquid properties checked in stages. "We won't just pop the lid," one official said. "It will take several days." The work is targeted for around the end of September, with a detailed schedule still being worked out.

This marks the first time a container designated for quarantine review has had part of a set placed in indefinite storage rather than fully processed. Kaname Tsuyuki, 56, chairman of the Preliminary Survey Association — a former appraisal assistant at the Third Appraisal Center and the advocate behind the association's three-point code, "don't open, don't rush, keep records" — welcomed the split decision: "People assume appraisal is about settling things one way or the other, but there's room for treating things separately. Some of our members' own sites have chosen not to open, too."

The Fukagawa neighborhood association remained divided over whether to open the containers going into the session. One officer in his 60s who attended the Sept. 12 briefing said, "I understand both the people who want it opened and the people who'd rather it were left alone. Hearing that not everything will be opened this time — that took some of the weight off." Another resident was less at ease: "Something's still going to open next month, one way or another. That doesn't feel settled to me."

No new analytical results were announced at the Sept. 12 briefing, and both the mystery of the liquid surface and the question of the lettering differences remained at their previously reported "unexplained" level going into Tuesday's session. The board confirmed it would keep a record of concerns raised in that session's Q&A — chiefly, ensuring safety during the opening procedure and calling for prompt disclosure of results.

The Third Appraisal Center had previously said full academic data on the Fukagawa containers would be released only after the review board reached a conclusion on opening. Following Tuesday's decision, that release is now expected after the opening work is complete — likely sometime in October at the earliest — and is expected to include detailed isotope figures and a comparison of the engraved lettering. A center official would only say: "Opening one container might let us say something about the other two. Or it might mean we can say even less. We can't tell you which, right now." Whether the liquid's behavior or the lettering's origin, both may still end in the same conclusion even after the container is opened — that no one knows. The board plans to hold another briefing for Fukagawa residents once the opening is complete.