Momiji Sohma (草摩 紅葉, Sōma Momiji) is the rabbit of the Chinese Zodiac. When he first appears in Fruits Basket, he is about to enter 10th grade, and towards the end of the series he is entering his third and final year of his time at Kaibara High.
Momiji appears to be the most child-like in the series, easily mistaken as an elementary school student when he was really about to enter high school. Tohru also compares Momiji and Hatsuharu in her mind when she realizes that Momiji is actually the same age as Hatsuharu and that they are both one year younger than Yuki and Kyo. Tohru compares their height and maturity level and is convinced that they are completely different from what she thought. In the spring, Momiji and Hatsuharu are expected to attend the same high school as Tohru, Kyo and Yuki.
Momiji has blond hair, which was inherited from his mother, and brown eyes; most of his physical features were from his mother. For a large part of the series, Momiji is seen wearing childish, lacy, ruffly clothing. He wore the girls' uniform at school with shorts instead of a skirt (though was seen near the end of the series wearing the boys' uniform, looking more mature), which prompts Kyo to hit and yell at him. He has been seen with painted fingernails, and studs in his ears. Momiji also wears hats a lot.
Momiji is fifteen years old and almost always bubbly, cheerful, and fun. In the anime, he is seen playing "Cops and Robbers" with three older boys in the school hall. He came from a rich family, as his father is a businessman. Momiji is also considered as one of the most successful among the boys of the Sohma clan. He is very cute, but there is a somber side of him that not many people see. That is almost certainly because his own mother doesn't know that he is her son.
When people cursed by the Zodiac are born, they are born two months prematurely. When Momiji was born two months early, his mother was very worried, and as soon as she held him, he turned into a rabbit. She was so confused and was frightened by the transformation. She tried to love and care for Momiji, but it was too much for her to handle. Sometimes she would snap, and hit or scream at him. Soon, Momiji's father convinced Hatori to erase his wife's memories and ultimately forget Momiji, her only son.
After, Momiji's mother just thought he was someone else's son from the Sohma family (she asks Momiji if he should be going home soon in his father's office building and was concerned about his mother worrying about him). Momiji practices the violin, but was pulled out of class by his father when the latter found out that Momo would be attending classes taught by the same teacher. Momo is curious about Momiji, once remarking to her mother that she looks just like him. Her mother brushed it off, but Momo remains suspicious of Momiji. Momiji is often seen as cheerful but when it comes to his mother, he is often mature and calm and often quite sad, knowing that he cannot call her by who she is to him, his mom.
He cares a lot for Tohru, and is quite taken by her, such as when he hugged her before being formally introduced and promptly created a large ruckus at the Onigiri festival. Momiji often teases Kyo that if he doesn't get to Tohru soon, he will take her for himself, causing Kyo to get very mad and hit him or call him a name.
Momiji is German-Japanese (Japanese on his father's side, German on his mother's). Momiji also speaks German in the manga series. She and Momiji's father met in college. Their entire relationship went well until Momiji's birth. Those possessed by the Sohma curse are born two months early. This alone put a great amount of pressure on Momiji's mother, and to make things worse, when she tried to hold him he transformed.
At this, Momiji's mother broke. She was unable to smile, and she would snap when ever she saw him. It became so bad that they had to erase her memory. Momiji believed that, no matter how awful a memory is, it shouldn't be erased, but in order to help his mother recover, he agreed to have Hatori erase her memories.
During Summer Vacation
When going camping at Sohma's summer house, he and Tohru scavenge for beetles, along with Hiro and Kisa. Akito visited the house before he left, to visit Tohru. Momiji tries to protect Tohru from him, and when Momiji is struck by Akito, Tohru, who was out for some fresh air, stepped between the two. She is then also injured by Akito. He then apologizes, after he runs to get the adults' assistance.
After Summer Vacation
In Volume 13, Chapter 74, his younger sister, Momo, grows suspicious of his resemblance to her mother ever since they first met at their father's office building. His father immediately pulls him out of violin lessons, because Momo is going to the same teacher and she is asking about him. On Tohru's way to find out whether Kureno Sohma is the same Kureno that Arisa kept mentioning, she catches Momo sneaking into the Sohma grounds to watch Momiji play his violin.
Tohru talks to her, and Momo reveals that she has been stalking him from afar for a long time. She wants Momiji to act as her "big brother" and asks Tohru to tell Momiji. Tohru promises she will. When she tells Momiji, this causes him to cry because he is so happy that Momo would want such a thing.
Momiji Grows Up
In Volume 19 (Chapter 111), Momiji has grown very much, looks very mature and wears the boy's school uniform. However, he still wears his rabbit backpack and acts childish (i.e. being excited over ice cream). In fact, he walks with Tohru and holds her hand. Most of their classmates are surprised when they see him, Tohru saying it's because he "grew so fast and became so handsome". Momiji gets excited when told this and goes on to say how being small was convenient at times but that it's good he grew because he's "a man, after all". It is hinted he has developed romantic feelings for Tohru. He even tells Kyo in the same chapter that if he, Momiji, becomes more handsome and taller that maybe then Tohru will accept when he proposes, going on to say that neither one of them should give up. In this volume, Haru noted that Momiji and Tohru looked like a couple from any angle as they are still very close, and hold hands while walking.
Breaking of the Curse
In Volume 20, Chapter 115, Momiji's curse is broken. He is the second one (after Kureno) to have it broken.
Akito realizes that his curse was broken and begs Momiji to stay. However, Momiji tells Akito that he will come back to him next time. At school, Haru, Yuki and Kyo realize that Momiji feels 'different', even late for school, though he was his usual self. He stands alone across a school corridor and watches Tohru talking to Yuki and Haru. Kyo arrives and informs him that the other two were worried about him as well as himself. Momiji sees clearly how Tohru feels about Kyo, and naturally, Momiji feels pain that the person he loves is in love with someone else. Momiji then informs Kyo that his curse was broken (hence the strange feeling between the four of them) and tells Kyo with a sad smile on his face that Tohru would be happier if Kyo's curse was broken.
After school, Momiji came back to Akito and he told her that he cannot live by her side any longer as he was no longer bound to Akito by any means. Akito slaps him on his left cheek out of anger and scolds him, saying that if he leaves, he will have nowhere else to go and call home. Despite this, however, Momiji decides to move forward and have hope in his future, regardless of the pain he is feeling from the many circumstances around him.In the last chapter, he had told Haru (with Rin nearby) that he wants to find a girlfriend as cute as Tohru and show her off to Kyo. He has matured in both appearance and attitude, though this is sort of sudden (though it might be attributed to the fact that his curse is broken). In Fruits Basket Another, it was revealed that he has a daughter named Mina, she loves baseball and is very good at batting. She also revealed that Momiji is a businessman as he's always traveling for business. It's also revealed that his sister Momo now knows that Momiji is her older brother, we can assume he's also reconciled with his mother.
- Momiji's rabbit form has red eyes, but is not completely white, because his fur color is influenced by his German descent. This means his rabbit form may be partially albino.
- He seems to take after his mother a lot more than his father in personality and looks. Momo has noticed this, telling her mother that he looks just like her.
- Momiji was intended to be named Kureno, but due to a mix-up, was dubbed Momiji. The author says that she feels good about this, because the name Momiji fits him better.
- The vision the girls in student council have of a more mature Momiji turns to out to be similar, if not identical, to the real grown-up Momiji.
- He seems to be very similar in appearance and behavior with Ouran High School Host Club's Mitsukuni Haninozuka, also know as "Honey". Both are childish, cute, blond and somehow associated with rabbits. Momiji turns into one while Honey loves his stuffed bunny named "Usa-chan". Interestingly, they share the same seiyuu. He also has a similar behavior and appearance as Sealand, from Hetalia. Both are in some way ignored, Sealand is ignored as a country and Momiji ignored by his mother.
- Its seems toward the end the end of the series's, Momiji's relationship with Tohru seemed to shift from a close friendship, to a crush, this was noticed when Momiji told Kyo that if he wasn't going to propose to Tohru, he would, although kidding, he seemed as if he had a seriousness to him.
- In Japanese, 'Momiji' means maple tree.
- In Momiji's song he says "the birds and the bees sing Momiji", perhaps this line is referring to the English idiom, the birds and the bees.