Pleasant read. I got a little confused by the end, but I think I got the gist of it. The art has a real... peaceful sense to it.
So my understanding:
- an alien ship malfunctions, and its crew escape in escape pods (which later become known as
amafune, celebrated in the festival at Kusudo in chapter 2).
- when the crew awaken and emerge into Earth's atmosphere - something which happens on a staggered schedule, hence the different memories from the different crew members - their bodies cannot fully survive for longer than seven days before dissolving, leaving only their Cores (crystallisations of the ore that makes up their skeletal systems) in which they live on as a memory. Due to their flowing robes and beautiful imagery, they are mistaken as gods, giving rise to the
tennyo legend common in Buddhist folklore. The girl in chapter 5 can understand 5056 because she has a translation headset, presumably salvaged from a previous
amafune by someone in her village as they have a history of coming into contact with
tennyo, hence the festival already held in their honour and the previous memories from older Cores that are communicated to 5056.
- one of the crew decides to fuse their Core into human women to ensure the preservation of their memories, rather than their Core presumably being lost as they are vulnerable to fire. The resulting fusion creates the Settled Ones, who physically embody the memory of said Core; their skeletons are made out of Core, and the vestiges of the original crew's memories are passed down through them. What remains of said Core - which now seems to be partly organic through the fusion process? - preserved by the Settled Ones, and powers the "danger level" checker - attached to the translation headset seen in chapter 5 - used by them in chapter 3 to test Yajuumaru.
- the Settled Ones bury the physical remains of their dead on top of a mountain, in a lake (the word used in Japanese is "swamp" which I deliberately avoided translating because I don't think it is...) where an
amafune once sank, as seen in chapter 3. Because their remains are made of the same substance as the aliens' Cores, they still live on after death, and through manipulation of magnetic fields they are able to communicate, attempting to reach the aliens' homeworld. Teora buries Shino in the same place in the Celestial Funeral in chapter 4, and we see the burial grounds again in chapter 5.
- a Core is the "bell" used in the Bell Hunt of the Ikuno Maidens in chapter 1, hence why there are stories of it speaking to those who hold it - because it contains the memory of one of the original aliens.
It's slightly unclear, however, that there is a
massive time skip in chapter 5. Teora says to 5056 that it's going to be a long, long time before humanity is able to transport it home, as the technology isn't there in 2030. The final two pages take place far, far in the future, as is clearer from the bonus chapter I'm about to upload.