Momo Sohma

is Momiji Sohma's younger sister, who was born after their mother requested to forget all about her son. Although Momo herself is unaware that she has a brother, she is very attached to Momiji and wants to get to know him, despite her father constantly interfering with her progress.

She reappears in the sequel, Fruits Basket Another, now as an adult and aware that she and Momiji are siblings.

Appearance
Momo is a young girl with goldish brown eyes and wavy, shoulder-length, dirty-blonde hair with straight, evenly-cut bangs that cover her forehead; all of these traits being inherited from her mother. She is often seen wearing accessories in her hair; during her introduction, she has a portion of her hair tied into a side braid with a yellow ribbon. Later, she is seen with a hairband with a ribbon on top.

In adulthood, Momo has grown significantly taller and has her similarly short hair in the same hairstyle, though her bangs are messier and frame her face.

Personality
During her introduction, Momo is seen to be very shy, quiet, and almost never speaks. According to Momiji, since German is her first language, she can't speak Japanese very well to the point her words sound like she’s muttering softly. When she meets Tohru again, Momo is seen to be quite expressionless, yet is very caring and kind-hearted as she lets Tohru into the Sohma Main estate, even though it isn't allowed to do so. She is also characterized by her love towards Momiji, as although she is forbidden from meeting him by her father, Momo still wishes for him to be her older brother.

In Fruits Basket Another, Momo is seen to have grown out of her shyness and is much more outgoing and openly affectionate, especially towards her niece.

Second Year Arc
Momo meets Momiji for the first time at her father's office building. Momo clings to her mother tightly while her mother talks with Momiji and Tohru Honda. Before parting ways with them to meet up with Momo's father whom she and her mother had been waiting for, Momo stops and curiously looks at Momiji before being dragged along with her mother. Tohru later understands that neither Momo nor their mother doesn't know of their familial relationship with Momiji.

When Tohru goes to the main house in order to find Kureno Sohma, she finds Momo, who says she knows a secret way in. They go into a tunnel in the wall that leads to Momiji's backyard. Tohru wonders how Momo knew the way in, to which Momo replies that her friend from the "inside" taught her about the way since other people wouldn't let her in the gate. Momo, knowing that Tohru is Momiji's friend, reveals that she secretly comes to watch Momiji play the violin. Momo also tells Tohru about how similar she thinks her mother and Momiji are, a remark which her mother previously brushed off and her father disliked. However, her curiosity only amplified, leading her to ask Tohru if she could ask Momiji if he could be her older brother. Tohru later meets up with Momiji and tells him about her conversation with Momo, prompting Momiji to cry from happiness. However, he also says that he cannot go along with Momo’s wishes.

Third Year Arc
Momo is mentioned by her mother, who explains to Momiji that Momo is looking forward to their upcoming family trip.

Fruits Basket Another
Momo reappears in the sequel, now an adult. She is seen picking up her niece Mina Sohma from the batting center. Mina introduces Momo as her father's younger sister and that she is his assistant. Momo tells Mina to hurry since Momiji would be returning back to Japan from his business trip. This confirms that Momo has reconciled with Momiji and knows he is her brother.

Mother
According to Momiji, Momo follows around her mother like a baby chick and always sticks by her side.

Momiji Sohma
Ever since their first meeting, Momo has been very curious about Momiji. Momo thinks that Momiji and her mother are similar in terms of appearance, which is why Momo wants Momiji to be her older brother. Momo's pursuit of spending more time with Momiji has lead to her trying to speak with him whenever she can, signing up for violin lessons to get closer to him, and even talking about attending his high school in the future. No amount of her father’s interference deters her from her goal. In the end, she even asks Tohru if she could ask Momiji to be her older brother, something which makes Momiji overjoyed. However, Momiji explains that he cannot go along with Momo’s wishes, afraid that it will break their family’s current happiness apart again.

In Fruits Basket Another, however, it is revealed that Momo now knows that Momiji is her older brother. Momo loves and respects her older brother, and since she is his assistant and is close to his daughter, they are implied to spend a lot of time together too.

Mina Sohma
Momo is very close to her niece, Mina. She is implied to spend much time with Mina and regularly checks up on and cares for her while Momiji is out on business trips.

Trivia

 * Although it is initially stated that Momo is in her second year of elementary school, Momiji later mentions that his father is troubled as she states her interest in attending Kaibara High School (likely in pursuit of Momiji). He states his idea of intentionally repeating a year so that they can attend the same school. However, this would suggest that Momo is actually only 3 years younger than Momiji, making her 11 or 12 at the very start of the series rather than 7 or 8.
 * She is the first of the Sister Sohmas to appear in Fruits Basket Another, the second being Hinata Sohma.

Momo Sohma Momo Soma Momo Soma 相馬もも