Gekkou (a Touhou LW original) refers to a moonbow, a rainbow produced by moonlight. The temperament is a good fit for Luna Child, the fairy of moonlight. Luna Child is endowed with Water Phase, from her hardworking nature, and Moon Essence, from her intellectual inquisitiveness that goes beyond a normal fairy's. The flexible and patient Water Phase resists Metal Phase, because metal collects water, but it is weak to Earth Phase, because earth directs water. The cooperative and indecisive Moon Essence resists the alluring and arrogant Sun Essence, but it is weak to the diverse and uncooperative Star Essence.

Luna Child's ability might not seem very useful, but be careful! Hearing is your most powerful sense for things that are out of sight, so you could say that Luna's ability can create "blind spots" for things you cannot see. It is very helpful in pranks as well as for running away after a prank. The ability also extends beyond Luna and her allies―she can mute the sound of everything around her. This can be a terrifying ability, especially at night... If one direction seems strangely quiet, Luna is probably standing there, getting ready to play some pranks. However, since sound is also a kind of wave, this ability probably does not work against a particularly someone who can manipulate waves...