Houseki no Kuni (宝石の国, Land of the Lustrous)Episode 05 has been aired.
New mysterious characters appeared.
This anime is very beautiful, but difficult to understand.
I’ll give you an explanation, with a spoiler.
Phos has been lost and every jewels are looking for him.
Diamond asked Cinnaber to find him.
Phos is brought to the Lunarians!
This is a new character, King Ventricosus.
She can communicate with the Lunarians.
But the Lunarians attack her.
A strange creature is coming up and drives them away.
It’s her younger brother, Aculeatus.
They are the ethnic(?) of Admirabilis from the sea.
In original Manga, they told a legend about this world.
All human was destroyed by 6 times of meteorite crashes.
At the 6th attack, human moved into the sea and they are separated into 3 pieces – soul, flesh and bone.
Bone had developed to be Jewels with inclusions. They are human-shaped on the land, consume the light for nourishment and are immortal. There are only 28 individuals.
Flesh had developed to be Admirabilis with shells. They live in the sea with a shape of marine invertebrate and turn to be a human-shape with tentacles on the land.
They reproduce and die in the short term, but carry on their intelligence. Their bodily fluids can melt Jewels. Most of them has been captured by the Lunarians.
In EP05, Ventricosus had intention to take Phos to the Lunarians to get Aculeatus back. But Aculeatus returned to consciousness and attacked them.
At the last of the episode, Rutile transplanted bars of agate to Phos’s legs.
These agates were suggested to be given by Ventricosus’s shell.
Ventricosus thinks that the Lunarians are composed with only soul and want to capture Jewels and Admirabilis to return to human.
It remains a mystery.