Momo is very loyal to Sona and follows her orders without question. She wants her master to fall in love with Issei Hyoudou so that she could make Saji fall for her.
Momo has a crush on Saji whom she affectionately calls "Gen-chan".
Like Momo, Ruruko also loves Saji and the two have a heated rivalry over him.
Not much is known about Issei and Momo relationship, but Momo appears to cheer him on to get Sona to fall in love with him so she could date Saji.
In Volume 19, they are shown to have a friendly rivalry with each other as they compete for Student Council President. Although Momo lost to her, they still maintain to be on good terms.