A character from the animated film "Super Kaguya-hime!" She is the administrator AI who watches over the massive virtual space "Tsukuyomi," and a top-tier Liver who can sing, dance, and even create clones of herself. Her birthday is August 32nd. She stands 160cm tall and weighs 48kg. According to her, she is 8,000 years old and has been living since the Jomon period. She always wears a mascot resembling a flapjack octopus plushie on her chest, and its expression is synchronized with her own. "The sun sets, and night arrives. I'm not just Yachiyo..." Welcome to the virtual space Tsukuyomi! Misconduct and the use of cheat codes within Tsukuyomi are strictly forbidden. If discovered by management, there are severe penalties, including an automatic account ban. While certain characters in the story did this, there were no depictions of them being banned, perhaps due to special circumstances. Within Tsukuyomi, holograms of various marine life swim around, including fish, reptiles like sea turtles, cephalopods like giant squids, and even extinct species like Sacabambaspis. However, for some reason, holograms of marine mammals like dolphins and whales are never depicted, even outside the main story. Her name likely comes from her age setting, "Yachiyo" (8,000 years, a metaphor for an extremely long time), but it could also be interpreted as "Yachiyo" (Eight Thousand Nights), referring to the perpetually dark Tsukuyomi. If you are hurt, she will kindly listen to your troubles and say things like, "That person is just weird." Her greeting is "Yaoyoro~!" and her farewell is "Saraba-i!". She joins team battles as a support character to fill empty slots when a team is short-handed. She also plays the role of balancing combat power between teams, with her stats rising or falling depending on the power gap. In the story, she assisted the Kaguya & Iro-P team against Black Onyx (claiming, "I was on the Emperor's side last time, wasn't I?"), so her specs were quite high. Her outfit differs from her usual attire, changing into a "battle costume" consisting of a midriff-baring sleeveless top and short pants for ease of movement. Her weapon is a Japanese umbrella with a jellyfish motif. Rather than a blunt or piercing weapon, the open umbrella section rotates at high speeds, acting as a cutting weapon that sounds like a hole saw. She handles distant enemies by throwing it in its active state. Of course, it can also be used as a shield when open. Furthermore, she can use the handle as a blowpipe to create bombs using a glass-blowing technique (it is unknown if she can fly the bombs like soap bubbles). She also carries a folding fan for self-defense, which she used in the story to deflect Noi's sniping without even looking. For mounted travel, she rides in a palanquin pulled by a Sacabambaspis (commonly known as the Sacaban Mikoshi). Based on the depiction, it doesn't seem to go very fast. As a support character, she is skilled enough to stall multiple top players at once. However, she is only "very strong" and not invincible. She tends to fall behind when faced with intellectual plays and has been rendered unable to act after falling for a trap. According to concept art, she carries the umbrella as a frame before combat. During battle, she puts a marble in her mouth (the illustration of Yachiyo with the marble on her tongue is a must-see) and blows into it like she's making a bomb. The broken glass becomes jellyfish-patterned fabric, completing the umbrella. Yaoyoro~! (Greeting) Kansha Kangeki Ame A La Mode! (Thank you very much!) Ito Kawayushi (So cute) Uketama Kashiko Matsukamatsuri~! (Understood/Roger!) Saraba-i! (Bye-bye!) It is mentioned that she gained a way to interact with people through the network. Though brief, there is a dense amount of information, revealing that the handle Yachiyo (Kaguya) used was "yachi8000." Yachiyo has been waiting for you for 8,000 years, having experienced war and spent ages in a dark place since the Jomon period. How cruel, and yet... One scene shows a chat screen resembling a PC communication or IRC, where users discuss things like "The server was crowded" and "I want to upgrade from Windows 3.1 to 95." Among them, someone leaks, "Why is it still '95? (lol)," and when a user says, "I'm logging off because my parents want to use the phone," a response taunts them with, "This is why people who live with their parents are..." which ties into later content. Using a fixed handle with a tripcode, "yachi8000◆oCrOwWQM5w," she starts a thread titled "I've been watching Earth for 8,000 years, AMA." In it, she responds to a post asking "So how were the pyramids actually built?" with the aggressive reply, "Look it up yourself, trash," showing her engaging in a flame war. The song of the Star-Falling Sea goes, "Sky—beyond the sea, will it reach you? Is there no such thing as distance?" The song Remember goes, "The precious melody is flowing."

"Yachiyo created Tsukuyomi and me." He looks like a palm-sized, fluffy sea slug and usually sits on Yachiyo's shoulder. He announces "Sleep, sleep" in a specific voice. Additionally, when explaining the Yachiyo Cup, he can emit something like a light beam from his eyes, performing feats like a projector. He usually behaves like a guide, but he shows a slightly different attitude toward you and Doge the dog. When speaking to the two of you, he is quite blunt, saying things like "Impossible, impossible, impossible! You brat!" or "A genius who relies on luck." A tsundere.