I'm a fan of this mangaka's art, but some of her manga are a bit lacking in the story department. This manga is more of a carefree, so many plotholes kind of manga where you just have to say to yourself, "Well, I guess that's how it is."
Chieri is a young girl in high school when two of her school's idols confess to her. Immediately following their duel confessions, her older sister leaves her daughter in Chieri's care due to both her and the baby being in danger. So the two guys obviously want to take care of Cheiri and the baby, Momo. Momo is incredibly cute, but she doesn't feel super important to me in the story. She occasionally gets riled up and makes me a bit annoyed. The annoyance to cute factor is out of balance in favor of annoyance. That, and her mother, Cheiri's older sister, is an incredible bitch. There is no redeeming factor for her in the story. She's just a plot device to dump Cheiri with a baby.
The two male protagonists... have very unimpressive reasons for falling in love with Cheiri. It makes me facepalm to be honest. So little care was put into developing that part of the story. It's like they came up with the idea, "Two guys with the hots for young clumsy girl get into hijinks when girl is forced to take care of baby," with little care for the actual love aspect.
It's an open ending, and it's not confirmed whether she ends up with one guy or the other. There's a certain part of the story which leans towards one of the characters (at least, from my perspective), but it doesn't go any further which makes me think the mangaka was going to choose one of them, but then wimped out since she didn't want to make a good amount of readers upset. I really dislike open endings, even more than main heroine falling in love with the guy I wasn't rooting for. It's sloppy and lazy to me. Choosing one is bound to make some people a bit upset, but now we just have everyone with lukewarm feelings about the ending. It's almost a waste.