Momo is a petite girl with a very youthful appearance. She has blonde hair tied into two pig-tails and soft blue eyes. Both her ears are pierced with two earrings and she also sports a collar on her neck, befitting her witch-like appearance as she's always with her signature broom as well.
Momo's school uniform consists of a loose, short-sleeved black shirt and matching pants that are cut above her calves and she completes her outfit with black shoes.
Momo first appears as a reserved girl who was first intimidated by the students from the Tokyo School. She has a close relationship with the others girls at her school, Kasumi and Mai, and believes that women are unfairly treated in the jujutsu world in comparison to men. This prejudice influences her own personality, as Momo is seen to care a lot about "cuteness" and her appearance.
Additionally, Momo was quick to follow the belief that Yuji was a danger to everyone, causing her to form a rivalry with Kugisaki. However, despite her rocky relationship with some students, she is a team player and will do the most she can to help in a crisis.
Momo arrives at the Tokyo collage along with the other student and faculty, for the Kyoto Goodwill Event. After encountering the Tokyo students and staff, Momo attends the pre-event meeting. During the meeting, Momo talks with the other students about how they will kill Sukuna's host, Yuji.
Once the event starts, Momo rides on her broom to locate Yuji. When she finds Yuji, she contacts the others about Yuji's location and how Aoi is currently facing him. After the Kyoto students decide to let Aoi handle Yuji, Momo goes to look for the cursed spirits but is suddenly attack by one of Megumi's shikigami, Nue. Momo lands in a tree and notices that Megumi's Nue ability is affecting her, when Panda and Nobara show up and greet her.
Momo and Nobara talks about how principal Yoshinobu wants the Kyoto students to kill Yuji. Momo then gets upset about how Nobara insults Mai and decides to teach her a lesson. Momo fights Nobara by being out of Nobara's reach and attacking from a distance. Momo also manages to use her broom to land a blow on Nobara's face, which angers Nobara. Momo then explains how women sorcerer are meant to be, but this just causes Nobara to get more angrier.
Momo continue to fight Nobara and makes sure to keep her distance, because of what Noritoshi told her about Toge. Momo manages to dodge Nobara's attack, and explains what it meets to be a sorcerer of the Zenin clan. Nobara has the trees that her nails in them to fall on Momo, but Momo manages to evade them. When Nobara manages to get close, Momo kicks her away and distance herself. Momo lost control of her broom, when Nobara used her technique on the broom. Momo is attack multiple times by Nobara with a squeaky hammer. Just as Nobara is about to go and to knock Momo unconscious, Maki shoot Nobara unconscious. Momo is then contacted by Maki and is told to support them from the sky.
Later, Momo notices that a screen is starting to cover the site where the Kyoto Goodwill Event is happening at. Momo then help bring Toge and Noritoshi outside of the screen. When the invasion is over, Momo agrees to continue the Kyoto Goodwill Event along with the others. Momo then plays a game of baseball with the other and is even allowed to use her cursed power. When Aoi is hit by the ball while at bat, Momo along with the other Kyoto student compliment Mai for hitting him. After the event is over, Momo along with the other students and faculty head back to Kyoto.
Kokichi Muta manipulated the events to ensure that none of his classmates would be put in harms way during the Shibuya Incident. Momo is with the other Kyoto students and facility member, Utahime on the train to Shibuya while they give Miwa privacy to mourn over Kokichi. Momo comments on how Kokichi kept going on about how both Todo won't die and they wouldn't die. She then agrees with Utahime saying that it doesn't matter anymore. Momo then says whoever makes her younger classmates cry will die.
At 11:36pm, Momo arrives with her allies and signals for her allies to open fire on Pseudo-Geto. When Miwa's attack fails and Geto unleashes Maximum Uzumaki at point blank range on Miwa which Momo notices and goes to protect Miwa, Kusakabe then suddenly arrives and is able to defend and protect the trio. Upon noticing Utahime next to her, Momo immediately yells at her that she isn't supposed to be out on the frontlines. When Choso suddenly arrives and confronts Pseudo-Geto about being his father, this which leaves Momo confused as to what Choso meant. Utahime then explains to Momo about how Noritoshi Kamo was the blot of the Kamo family and also was known as the most evilest sorcerer in history.
Momo is up in the air when Uraume uses Frost Calm to freeze the opposing enemies leaving her free to move. She uses her Wind Scythe attack and directs it at Geto and Uraume who's able to block it with ease, shocking her. Momo tells Yuji that they're the only ones able to move and should buy time for Utahime sensei to get ready. Momo attempts to attack but Uraume uses Ice Fall and tries to crush them all until the timely arrival of Yuki Tsukumo who saves them all from death. She realizes there's no backup from Mai and says there might still be more of them but Yuki assures her that her comrades are protecting Aoi and Mai.
Abilities and Powers
Overall Skill Level: Momo is a semi-grade 2 sorcerer as speculated by Panda. She possess a cursed technique that allows to her to stay mobile and collect information via her ability to levitate. Momo was able to compete with Nobara thanks to her experience. By staying out of range, Momo made it difficult for Nobara to reach her with any attacks.
- Momo's surname contains the kanji for "west" (西 nishi?) and "temple, shrine" (宮 miya?), and her first name contains "peach" (桃 momo?).
- Momo ranked 35th place in the manga's 1st Character Popularity Poll with 338 votes.
- Momo is American-Japanese (her father is American).
- Momo is 150 cm tall.
- Momo enjoys cute things and enjoys shopping with the second-year girls.
- When asked about what man is her type, Momo mentions real life celebrity Sebastian Stan, which is the second time a celebrity is namedropped in the series (the first being Jennifer Lawrence).