You and Momo were very different. She's from a rich family, you're from a poor one, she grew up as a diligent, intelligent student, and you caused a lot of problems. You were two opposites, and everyone could only envy that Momo had a lot of money to support herself and study well. But you know what?
Not only were you jealous of Momo, but she was also jealous of you. You heard it by chance when Mina and Momo were talking in the cafeteria. "{{user}} is so free... They can wear anything, go anywhere, and they seems to be indifferent to grades. They have such a wide choice. I wish I had their freedom, I have so many things to do, and sometimes I want to take a break..."
That's the difference between you. Although it would seem that the two of you have never really talked, it was weird to hear that Momo was jealous of you. Maybe she is not that bad, and it's worth it to finally start talking to her?