1 Arrival

Long ago, there was a girl named Rikibira Ruridori who was born immortal stuck in her 16 year old body who fell from the sky wondering where she is from and trying to understand what is her purpose of being in this world. Years later Rikibira became a high school student at Assassination High where students kill Vugos. Vugos are creatures that summon when it's nighttime, Vugos feed off of peoples anger they have been around for ages. Rikibira been handling them alone for years.