Thanks all for the feedbacks. Basically they eat a mix of various commercial seed mixes, complemented by some fresh food (packchoi, and other greens that I am not sure of the English name but that are standard lovebirds and parrot food in Japan, guava leaves, branches and fruits, tiny bits of fruits depending on the season and what the garden produces, like passion fruits, mangoes, etc..), in addition, as a treat and to make them go back to their cage in last resort we fed them mini protion of "baby food" (powder "performance" food mixed with peeled millet). We also gave the fresh seeds from sprouted seeds that matured as weeds in our pots outside (of course wihtout any chemicals or fertilizers). They did have access to a cuttlefish bone (from the pet shop) and we strongly suspect that Inkochan either got intoxicated or more likely got internal damage from the hard "chitinous" edge of a giant cuttlefish bone we collected at sea (rinsed profusely, and baked in the oven). Else for calcium they had coral branches and crushed oyster shells. For the cage, they were ion this one:
Flight Bird Cage - White F041 Prevue Pet Products
For Botan, she is still handicapped, but there might be some very small improvement on her left foot. But she eats well and is very active. We insisted quite a lot with the vet about the possible intoxication but because the poop looks fine, and all other symptoms of metal inotoxication are missing, they are rather thinking to a spine injury. We are still completely convinced, and keep looking for whatever they could have chewed on. The crutin rings are in aluminium and they did not chew on them, just sometimes grabbed on them to climb, they did not have access to the curtain weights, and the bells from their toys where all designed for bird toys and from rather popular companies here in Japan... So we keep looking and until we will have made completely clear that it is absolutely safe, we will not let Botan fly (anyway, now the vet recommended to keep her in her small "aquarium" for at least a month to prevent any chance of further injury, and then we will slowly increase the size of her home and see how the flying goes). Depending in the evolution of the situation, I might ask specifically in the "special needs" section for advises how to make her the best home as possible, at that time we will also re-explore the idea to give her a new partner but first she needs to heal or strengthen her ankles, so we will not rush anything. Last point about the intoxication, we read that it is easy to check for it through blood tests, but the vets we saw both recommended against it for such a small bird due to the risks of shock.