Momo and Shoto have many similarities: both are students who got into U.A. High School through official recommendations, hail from famous (yet strict) hero families and both have powerful Quirks. As a result, Momo initially compares herself to Shoto and believes that he’s always a step ahead of her; not having self-confidence in herself. However, this also caused her to admire Shoto’s brimming self-confidence as a hero.
For his part, Shoto has respect for Momo's observation skills and natural leadership, even going as far as to vote for her during the Class President election, as he thinks that she’s fit for the role of being a leader. He later chooses Momo for his team during the Cavalry Battle in the Sports Festival, but she feels she was only following his orders and not doing anything by herself.
During the practical end-of-term test, Momo is paired with Shoto against Eraser Head. He quickly comes up with a plan of action, and Momo goes along even though she knows it has flaws. Throughout the exam, her low self-confidence causes her to panic and be indecisive. However, Momo regaines her confidence once Shoto, who was captured by Eraser Head, realizes she needs to be encouraged and so reveals he had voted for her to be class president. This inspires Momo and gives her the confidence needed to not only free Shoto, but also outwit and capture Eraser Head with his help, proving that they make a great team.
Momo and Kyoka appear to be close friends with each other. Along with Denki, the two battle against the Villain Alliance at USJ, proving that they work well together. Kyoka later asks Momo to tutor her for the end of term test, and she happily accepted.
When the class split went shopping for the training camp, they pair up and go off shopping together. Not only that, but Kyoka has also proven to be somewhat defensive of her. During the summer training camp, she punches Hanta Sero for comparing Momo’s Quirk ability to convert lipids at an atomic level into many different objects to defecation. She later joins Kyoka's band, playing the keyboard during the school School Festival and they pull off a wonderful performance with the teamwork of all of Class 1-A.
Momo despises Minoru’s perverted behavior, as he is often peeping at her and the other female classmates. She’s especially embarrassed during the U.A. Sports Festival where Minoru attached himself to her body using his Quirk in order to finish the race on time and to ride on her through the race. Also, he and Denki Kaminari trick her and the other girls in their class into wearing cheerleader outfits.
Momo and Izuku are classmates of Class 1-A and were both voted as the Class reps, however their partnership does not last long due to him stepping down for Tenya. Momo does not seem to have bad view of Izuku though she does count him out in the race in Vs. Hero Killer Arc however, she’s proven wrong and is amazed by his new mastery of his Quirk.
Izuku, along with Tenya and Momo, would later join Shoto and Eijiro to rescue Katsuki. Due to the group's teamwork, they’re successful. In recent story arcs, they seem to be on friendly terms with each other.
They are not interacting too much, though appear to be on good terms.
While Momo feels down after being tricked by Denki and Minoru, Ochaco comforts Momo on the matter.
The pair are seen talking with the other girls about things. Soon the topic turns into questions about Ochaco's love life, but Momo respects her privacy and tells the other girls to stop trying to pry into it. Ochaco’s greatly appreciative of this but is then left to wonder about her feelings.
Momo gets along with her, in spite of them being from different classrooms.
Itsuka and Momo intern together under Uwabami. Although they’re treated like Uwabami's entourage during their time together, Momo always tries to find a lesson in everything. Itsuka appears to feel sorry for Momo, seeing that she’s clearly in denial. 
Months later after their internship with Uwabami, she and Itsuka continued to be treated as a pair by fans. However, Itsuka didn’t like being lumped in with Momo because she feels Momo has a better Quirk and better grades. Itsuka has always wanted the chance to fight Momo head to head, and the latter accepts her friend's challenge.
Despite Momo losing the second round of the Joint Training Battle, Itsuka is unsatisfied and believes that Momo surpassed her. Later, Momo is accompanied by Itsuka to the Nurse's office. This shows that despite their rivalry, they are friends and care of each other.
Momo trains under Uwabami for her internship. She’s disheartened by the fact that they didn’t do any hero work and tries to convince herself that there was something she could learn from the experience.
- ↑ My Hero Academia Anime: Episode 34.
- ↑ My Hero Academia Anime: Episode 35.
- ↑ My Hero Academia Manga: Chapter 58.
- ↑ My Hero Academia Anime: Episode 28.
- ↑ My Hero Academia Manga: Chapter 198.