Chika Amagi (甘城千歌, Amagi Chika) is the main protagonist of SATANOPHANY. Chika was an ordinary 17-year-old high schooler until she was deceived by her senpai and was almost gangbanged. On the edge of desperation, Chika, however slaughtered the men who almost rapped her and two of her senpai who deceived her, killing five people in total. She was later sentenced to life and is now living in the Haguro Prison. Her inmate number is LB0009. Chika is one of the few girls said to have the Medusa Syndrome. Her "base" is that of an American serial killer, Henry Lee Lucas.
Chika has an older brother who went to study abroad. She idolizes her brother. Both of Chika's parents were always busy working and come home late. She was told by her parents to attend a ballet class, but Chika disobeyed them and frequently skipped the class.
When possessed by her murder model Chika becomes a quick and innovated fighter. She is highly flexible and quick from her training in ballet, such as when she dodged Karen's whip and Katya's knives at the last second giving off the illusion of teleporting, other times she was able to dodge point rank shots, dodge the fast slash of a criminal showing that she can make quick last minute decisions in an instant. Chika also has knowledge of human anatomy such as when she was able to bite Katya exactly at her carotid artery and even hit Karen right in liver knocking her down with one elbow strike. She's also an expert in unharmed combat as she was able to hold her own against Maki with a series of kicks while she wielded a shotgun. Another time she gave a criminal a high kick to the head with little effort.
What makes Chika most dangerous is that she is able to use and switch to many different weapons in a moments notice, without having prior knowledge or training of the weapon. This is shown when she killed those three men and her two senpais turning the items in the room into weapons. During the experiments she uses Katya's knives with no trouble and Maki's shotgun despite never holding a gun prior. When she runs out of bullets she immediately switches into using it as a club with wicked glee in her eyes. When she is attacked by Youko and the others she easily steals her weapon and strangles her by her own belt, not giving them a chance to catch their breath. She was even able to pull a loose blade chain from her skirt and strangle her opponent wrapping the chain her would be killer.
Chika has also been shown to use her own clothing in a fight. This is seen when she uses the top of her school uniform to block Karen's whip attack, another time she uses it to stop a criminal from using his chainsaw on her by throwing it into the blades. She even used the long dress of her wedding dress to blind Youko tripping her up before taking her weapon.
All of this combined make Chika a dangerous opponent a killer who can kill anyone with any weapon she can get her hands on.
- Chika actually shares similar traits with Medusa.
- Both were described to be incredibly beautiful before their transformation.
- Both were victims of sexual assault and were punished unjustly (Athena made Medusa into a gorgon after being raped by Poseidon while Chika was given life in prison.)
- Both have siblings that went on to fight for them. (Medusa's sisters wanted vengeance against Perseus, Chika's brother continues to fight for the truth of the Medusa Syndrome.)