Student Council President
|Strength||Extensive self-defense training|
She was first shown in the "December 15th Progress Update" video. Soon after, she reappeared in a video shown by a volunteer named "YandereAni" and was implemented into the game in the January 1st, 2016 Build. She is the most popular girl in school.
Megami has fair skin, light gray eyes, and long silver hair, down to her thighs with 'v' shaped bangs. She wears the default female school uniform, with black stockings, gloves and a choker with red stitching and bows. She wears the "Red Armband of Leadership" with Japanese text on it.
"Megami is the heiress to Saikou Corp, the most powerful business conglomerate in Japan. She is impossibly wealthy, a certified genius, has extensive self-defense training, has excelled at everything she has ever attempted to do in her entire life, and has been trained to possess all of the qualities of a perfect leader, to prepare her for the day when she will inherit her father's company. She is also the most beautiful girl in school, the most popular girl in school, and the student council president.
Megami has been absent from school for nine weeks under mysterious circumstances that she refuses to disclose. She has still managed to keep up with her schoolwork by attending class through a laptop, and has also been able to manage the school's student council by attending meetings via video call. She is noticeably upset about this; she strongly believes that she should be attending school like a normal student, and is resentful of her current situation, although she is not at liberty to explain the reasons for absence.
Megami, unlike all other characters, is fully aware of the fact that there is a dangerous person on school grounds. Once she arrives at school, she will do absolutely everything in her power to protect the school's population - that includes installing security cameras, hiring security guards, and instating a zero-tolerance policy for suspicious behavior. Megami clearly has some very important information that would cause her to go to such extreme lengths...but what does she know? What does Saikou Corp have to do with it? And, more importantly, what does Senpai have to do with it?"
Megami is going to be a strict disciplinarian.
She maintains a hostile attitude towards the player throughout her monologue, as she refers to them as a "vulgar creature". YandereAni has stated that in the full game, she will not be hostile if the player does not make a bad call. It is not yet known what a "bad call" refers to.
While her father tolerates her enemy's presence at the school, she herself does not and openly confronts them. It is unknown why she is acting this bold.
If the player is alone and gets close enough to the computer, she will begin speaking. It will shut off after she finishes her monologue, and will not turn on ever again.
YandereDev has said that her routine will put her in close proximity to Senpai or other students.
The rivals have been stated to each have a dark secret. If she has a dark secret, it is currently unknown what her secret is.
- Megami was inspired by Fujisaki Shiori from Tokimeki Memorial, Juliana Everhart from Valkyria Chronicles 2 and Satsuki Kiryuin from Kill la Kill.
- In the January 1st, 2016 Build, the player could move the camera angle while crouching so that the floor didn't show, and it was possible to see Megami under the fountain, sitting down, with a white wall behind her. That white wall appeared black from the north side of the fountain. When Yandere Vision was activated, she had a red outline, signifying that she was dangerous. She was subsequently lowered deeper beneath the fountain in the January 2nd, 2016 Build, before being moved to the south side of the school wall, far away and still below the ground in the February 1st, 2016 Build. As of the March 15th, 2016 Build, she is located behind the houses that are across from the school gate.
- If Yandere Vision is activated while Megami is monologuing, the speech will be slowed down.
- Though she will appear on the screen, she will not start her monologue if Yandere-chan is in the room with another student. She will only speak when Yandere-chan is alone in the room.
- Her name Megami means "Goddess" and Saikou means "The Best".
- When the rivals were introduced, Megami's name was initially misspelled as "Megami Saiko". This was confirmed to have been an error. 
- YandereDev's current reasoning for her absence in the first nine weeks of school is that she was being monitored by a family member, so that she will be prepared to inherit and operate the Saikou business empire. There will be more to it, however, YandereDev would not like to spoil what.
|“||Is someone there?...Ah! It's you...Why have you come here? Have you come here to taunt me? Do you even know who I am? I know who you are. I know WHAT you are. My father won't allow me to attend school while you are..."active". He has a reason for tolerating your presence at this school. I don't. You are a vulgar creature that is only allowed to exist because you serve a purpose. If it was my decision, then every last one of you would be exterminated. Have fun while you can. If you and I ever cross paths...you're going to have a bad time.||”|
— The caption shown in-game when Yandere-chan is seen by Megami Saikou in the Student Council Room.
|“||My top priority is to put a stop to anyone that poses a threat to this school! Senpai! I think someone may be stalking you. But don't worry...I'll keep you safe.||”|
— Megami in "Yandere Simulator Rival Introduction Video" 
|“||I heard rumors about a dangerous person causing trouble at this school. As student council president, it is my duty to find this person and put a stop to them. Senpai, don't be alarmed but I believe that someone may be stalking you. Don't worry. I won't let them harm you. You'll be safe with me. I promise.||”|
— Alternate Megami line for the "Rival Introduction Video".