Mika Kishi is one of the protagonists in the Towairaito Shindoromu and the main protagonist of Moonlight Syndrome. She is also mentioned offhand in The Silver Case and Pre-Lunatics.
Originally she is a cheery girl obsessed with rumors about the supernatural who frequently ropes her friends Chisato Itsushima and Yukari Hasegawa into going on investigations with her. However, one year later in Moonlight Syndrome she has seemingly grown up and is more interested in a regular life.
Mika to the left
By the end of Moonlight Syndrome, she is killed, her soul having been taken by Mithra; however, it can still communicate with Ryo Kazan using the medium of television.