I think this name is beautiful! I am currently studying Japanese and I think I might use this as my Japanese name, as I was born on a day of a full moon :) I also have always felt a strong connection to the moon and I think this name is very pretty!
Two famous bearers: Tsukiko Sagi, one of the main characters of the anime series Paranoia Agent. Tsukiko, the Japanese name of the weekday sibling Monica from Pokemon Gold, Silver, and Crystal.
Because the name "Tsukiko" means moon child, it would fit best to a girl born under the zodiac sign Cancer, because of Cancer's ruling planet, the Moon. This name can be used however people choose it to be used though. I wish this was my name, because I was born under Cancer. I really love this name.