A huge shoutout to the fantastic people over at Goldenskate's Twitter account, who have such wonderful practice notes! Since Twitter is currently a trash dumpster fire, I will attempt to summarize the information for those without Twitter accounts.
I was only able to find notes for the Japanese men, but all three were looking strong.
Shoma Uno opened his practice with a few shaky 4Fs, but seemed to have a grasp on them by the end. His runthrough was clean aside from a doubled 4Lo and a fall on the last 3A, but he successfully jumped everything in the practice following his runthrough.
Yuma Kagiyama also skated quite cleanly, just doubling his 4T and marking his second 3A. He also landed the rest of his jumps cleanly in practice, and was working on a 3Lz+3T that I can only assume will be his third combination in the free skate (he only did one combo in his runthrough and is doing two quads in the SP) in order to further increase his BV. He landed a 4F with a stepout at the end of practice, but will likely not be including it in his program on Saturday.
Tatsuya Tsuboi is looking far stronger than his first GP, stepping out of his second 4S and singling an axel but otherwise skating very strongly.
The women have far more comprehensive practice notes, although it looked to be a bit messy.
Mai Mihara is still dealing with pain. According to interviews with the Japanese press, she started feeling pain in her ankle during the offseason that worsened right before CoC. She says she wants to skate through the pain and finish with a smile on her face

. For her runthrough, she did no combinations and jumped a 3Lz and 3S - the rest of her jumps were doubles.
Wakaba Higuchi is looking strong, doubling a loop in her FS but otherwise skating well. She tried the 3A after her runthrough. None of her 10 attempts were landed cleanly, but she's planning on including it here.
Yuna Aoki, the third Japanese representative, landed a 3Lz+3Lo and 3F in her SP runthrough, and may be one to keep an eye on.
Nina Pinzarrone did not do any 3+3 in her FS runthrough, electing to do double toes on two of her combinations, and had a fall on a 3Lz.
Haein Lee popped some jumps and landed others in her FS runthrough, which looked to be a bit of a mixed bag.
Anastasiia Gubanova did her first four jumps for the FS cleanly, but then skipped the rest. Poor
Yelim Kim had a hook pop off her boot at the beginning of practice. She left to try and fix it, and apparently they have a repair service on the job. It should be a relatively easy fix, but she is missing out on quite a bit of ice time. Hopefully the organizers will let her get in some practice time later today.
I saw a video of
Yuna Nagaoka / Sumitada Moriguchi courtesy of
NHK Japan (requires Japan VPN). All I saw was a throw and a lift, but both were looking very promising. I don't expect them to be pushing for the podium or anything, but they look to be developing very nicely as a pairs team.