Aomine and Momoi have had a very close friendship since childhood since they live close together. As children they often played basketball together. Up until Junior High school, they were very close and were on first name basis (him calling her "Satsuki" and her calling him "Dai-chan"). To his discomfort, Momoi started to call him "Aomine-kun" instead, otherwise "people are gonna talk". Aomine himself said it felt gross that she called him "Aomine-kun". Their relationship grew apart slightly but they continued to go home together every day.
Their friendship was tested when Aomine started to get bored with basketball and his attitude started to cause trouble. Momoi stuck with him through thick and thin and also decided to attend Tōō High with him because she was afraid he would do something if she wasn't there to keep and eye on him. In the Character Bible, Aomine says that he wants to sleep in on his days off, but Momoi forces him to wake up and take her somewhere. It is shown that he does care about her very much but he lets his temper run away from him; when they had an argument about Momoi telling their coach to pull him off the team for injuries, he lost it and said that he didn't want to see her "or her ugly face" anymore. Momoi burst in to tears, flung a clipboard at his face, and ran off, calling him a ganguro. Aomine's reaction implied that he hadn't meant to make her cry and regretted it.
After Aomine was defeated by Kagami, he regained his love for basketball and asked Momoi to go shopping with him the next day so that he could buy some training gear. She smiles at this and starts to call him "Dai-chan" again, and adds that she will only do that if he buys her dinner. Since then, the two have been shown together more often.
Aomine is neither supportive nor against Momoi's crush on Kuroko, as shown by both the Replace novels and an omake in which Kuroko and Momoi went on a date. He was dragged by Kise to go spy on them and he was the one who worked behind the scenes to get rid of possible interlopers who wanted to hit on Momoi. He was even seen estimating Momoi's cup size (he guessed that she was E-cup at that time) after she made her appearance. After the date Momoi ran to his house to show off the stuffed toy Kuroko had given her as a present, Aomine was completely uninterested and he only responded with a "Yeah, yeah, congratulations." It was implied that Aomine already knows that Kuroko does not return her feelings (or is even aware) but keeps quiet as not to upset Momoi.
AoMomo is the most popular het ship within the fandom, it is supported due to the two being childhood friends and caring greatly about each other. Fans see Aomine as the "tsundere" in the relationship.
- The anime director has said about the duo: “When I think that perhaps at some point the time will come when one of them will start to notice the other as a member of the opposite sex, it makes me excited and nervous watching the two of them.” 
- In Kuroko no Basket's mobile game, Momoi pulls Aomine away from Alex as she is afraid that Alex will kiss him due to her habit of kissing people to greet them.
- Aomine is the reason why Momoi became a manager. 
- Aomine's VA Junichi Suwabe has also express interest in the paring. "She says she likes Kuroko but I expect she’ll be swayed by Aomine eventually. She went to the same school…(laughs). And Aomine is still in his first year of high school, so the feeling I get is that at the moment he acts like, ‘Not really? It’s got nothing to do with me’. But the situation will gradually change. Aomine never said anything to the ever noisy Momoi around him, but if he comes close to losing her for instance… it will hit him!"