|Appearances||Trigger Happy Havoc|
Celestia comes across as very cold and distant from the other students at the academy. She does not reveal much about herself to them. She is rather calm when talking about despair as well as the previous deaths in the academy, but can be very cunning, tricking Hifumi into his own death.
Celestia is very slim, pale and had red eyes. Her hair is bunched into two pigtails and are spirals, her hair is the most prominent asset on her character. She wears a gothic lolita type of outfit, black tights and red shoes.
Not much is known about Celestia pre-despair. During free time interactions with Celestia, Makoto learns that she regularly goes to a coffee shop to drink her favourite royal tea. She is also a professional gambler, who has not heard the word "lose" in a long time.
 Finding Mondo Owada guilty
Celestia proved to be key into finding Mondo guilty of Chihiro's murder. Celestia met the deceased in the storage room, prior to his death. Celestia noticed Fujisaki's blue jersey partially in his bag, which he then stuffs back inside before going off in to the gymnasium in a hurry. This later proves to be a major factor in finding out who murdered Chihiro.
In order to allow them to both escape and bypass the rule that only the "Blackened" can graduate, she formulated the plan in which Hifumi was to murder Kiyotaka Ishimaru and she murder someone else. In order to do this she convinced Hifumi that Kiyotaka had stolen Alter Ego and was planning to murder Hifumi and keep her all to himself, she also stated that Kiyotaka said some sexually explicit things to Celestia to add fuel to Hifumi's fire. Once Kiyotaka had been murdered by Hifumi, Celestia murdered him to ensure the plan remained a secret.
In order to cover her tracks, she and Hifumi (before Hifumi's murder) framed Yasuhiro Hagakure by knocking him out and placing him in a "Robot Justice" suit. Celestia then fakes Hifumi's death by making Hifumi to pretend to die, tricking the other students to look for the individual in the Robot Justice suit. During this time, Hifumi moved Kiyotaka's body to the Art room, where Celestia turned against Hifumi and killed him.
During the class trial, Celestia orders the other students into declaring Yasuhiro as the guilty party, but to no avail. Even though the Robot Justice suit did indeed fit Yasuhiro, the team demonstrated that it would be very difficult for Yasuhiro to bend when in the suit, therefore he found not pick up a body to move it. However, Celestia still insisted that Yasuhiro was the culprit, using the fact that Hifumi said the word "Yasuhiro" before his death. Makoto picked up on this and asked Celestia for her real name, since she had only referred to herself as "Celestia" (or "Celeste" in the European version). She refused and mentioned that it would not aid the investigation. Makoto was adamant and demanded to see her e-student book. After a few prods to do so, she did, revealing her name as "Taeko Yasuhiro".
She mentions that the reason as to why she killed in the academy was to get her hands on the money. Even though she was the Ultimate Gambler, Celestia had a dream to live in a mansion with people working for her. She did not have enough money in order to make this dream become a reality, despite being the ultimate gambler, she had fell on hard times. She then admitted to her crimes and she was found guilty and sent to death in the The Burning of the Versailles Witch execution.
Celestia proves to be very bossy towards Hifumi, ordering him to make her tea. When he does it wrong, she smashes her cup on the floor and says that she only drinks milk tea. The bossing around, of course, lead onto manipulating him to kill Kiyotaka in Chapter 3.
 Free Time
The following presents can be given to Celestia in order for your bond to grow with her, they are available from the MonoMono Machine:
- Rose-Hip Tea
- Love Affair Ring
- Crane and Tortoise Diamond
- Rose Whip
- Antique Doll
During getting to know Celestia better, she will ask you some questions. The answers to which are:
 Skills Obtained
The following skills, that can be used to aid you in Class Trials, are obtained after getting to know Celestia:
- Menacing Concentration
 PSN Trophies
- The French Disconnection (Complete Celestia's Report Card)
 Report Card
Celestia in a Class Trial