Typically in the series, the alter-egos that the users own or claim are often used during in the night.
The alter-egos that the heroes and villains predominantly consists of Noctambules-masques. While the rest are other heroes, inventors, ninjas, witches and mysterious girls.
Most of the alter-egos the people claim usually don't include in their real names, and often prefer to name and describe the alter-ego after the appearance of their nighttime clothes they're wearing, as well as their actions (sometimes). Examples include Yoyo, Ninjaka, Roméo Mécano or Tatouro.
Some of the nighttime alter-egos are vigilante-themed, considering them as "secret identities" in which they'll not reveal to the public who they're really are, and usually have the words "man", "boy" or "girl" inserted at the end of their alter-ego name. Examples include Catboy, Energuman and Luna Girl.