[Help!] Looking for a song :(

[Maemi]

Hello everyone, I hope someone can help me!

I have heard the part of this song many times until now, and I think it's kinda old and popular. It is sung by a female singer (at least in that part), and I'm not even sure if it's in english, because the lyrics are kinda messy to me, but I remember the words in refren and they go like "Mona, moona, mon..."

Thanks in advance!