Introduction
Many thanks to Twitter user LadyStarwing telling some of the nue related content here as well as this Chinese article
Nue features
Nue is one of the youkai in the Heike Monogatari. According to the records, we can see these in Utage's features as well as her E2 art, are also consistent with traditional nue depictions, with the only oddity being her more feline-like ears.
1. Face of a maned monkey: humans are related to monkeys too.
2. Limbs of a tiger: She even remarks on how she needs to keep her nails maintained, and those are very clawlike fingernails
3. Body of a tanuki: her summer skin shows that she's quite endowed under her baggy coat and sweater, which is an amusing nod to the fact that tanuki are often depicted with exaggerated features themselves
4. Tail of a serpent: self explanatoryOther Higashi native operators do not know what to make of her race, implying that nue aren't normally seen there. Which is a fun little nod to the fact that the most famous nue myth from the Heian era had it disguised as an ominous black fog over the imperial palace until Minamoto no Yorimasa shot it out of the cloud cover. It's name actually has no direct translation; the kanji used to describe it means both night and bird.
Sword
If you look at Utage's sword, SHISHIOH is written there. Shishiou was gifted to Yorimasa after the deed, but since he was an elderly man at the time, they took what would have been an odachi and instead made a thin/light tachi with expert craftsmanship to not insult the man.
Talk after Promotion 1: When I contracted Oripathy and was to be sent here, my mother was afraid I'd be bullied, and gave me the family heirloom, Shishiou, to defend myself with. Didn't find any bullies, but I did manage to cut some pretty nasty folks. Doctor, you really know how to appeal to people.
Space theme and summer costume analysis
There's a space theme in all of Utage's clothes from E1/2 to costume.
'Gravity' written in the sand for the full art of her skin: This could be another nod to the myth of the Nue as the Nue didn't actually die when Yorimasa shot it out of the clouds. But rather, his companion jumped on it when it fell from the clouds.
Other trivia:
-Her floatie being from the brand Marine-X is a shoutout to Space-X, which is a company that designs spaceships. The effect that appears with her 'Descending Strike' skill is an easy nod to the fact that the Nue always appeared in a dark storm cloud.
-The arts damage ties into that motif easily too. Lightning striking the roof of the imperial palace to start a fire can explain it's more flame-like appearance.
-Her first skill being 'Space Out' is amusing bc iirc the original Chinese was 'Take a break' so that just tracks with her being a teenager. But at the same time, spacing out is often associated with non-neurotypical brain wiring; you're not fully there and your brain isn't focused on any one thing. Her archive files note that Utage is "adept at disguising and manipulating her mental state" and that most normal psychological methods don't work on her due to such. It's not fully known if it's because of her as an individual or as a trait of her [Unknown] race which does track with the Nue: It was rarely seen, and when it was seen, usually only in times of great bloodshed and tragedy.