[sarasi]

While you might be thinking that "Gekka" is a pretty name because the kanji you have chosen mean "moon flower", it doesn't sound anything like a Japanese girl's name, and the word "gekka" with different kanji has several different meanings- one of them is "aggravation", so not really a nice-sounding name.

Seika also sounds a bit odd, and Umi isn't usually a name although it's not impossible.

Momo and Yumi are ordinary names here that lots of girls have.

Someone gave you a list with mostly more normal Japanese names, but one of them is Toru (or Tohru), which is very much a guy's name! Another one was "Toonami", which I haven't come across before, but it sounds more like a guy's name, or an anime name which you will never find a real person with.

I really wouldn't advise trying to make up your own name as you risk ending up with something which has a completely different and perhaps embarrassing meaning in Japanese.

Go with names that already exist.