Translation: The first kanji used for her surname, "mei", translates to "dark". The second kanji used "ou" translates to "king, ruler". Then, the hiragana used to make her give name, "setsuna", translates to "moment". So, her name would come to the translation of "Momentary Dark King".

The Momentary Dark King would make implications to connect Pluto to Hades in Greek mythology (Pluto in Roman mythology). Hades was the ruler of the underworld, land of the dead. Being connected to that myth might also explain her attack, Dead Scream. The name Setsuna would make connections to time and, in effect, her being the watcher of time. Also, Meiou-sei is the Japanese word for the planet Pluto.