Rikka's given name (六花) has the meaning of "standing flowers", a form of ikebana, the Japanese art of flower arrangement that was developed in late 15th century.
Rikka's given name (六花) also has the meaning of "snow". Her mother named Rikka as such because she was pregnant with Rikka during the winter.
Rikka's character concept i.e: wearing an eye patch,having indigo hair and a fondness over a character,etc.,may have been a reference to Chrome Dokuro from Katekyo Hitman Reborn!
She became a chunibyo after watching Yuuta/Dark Flame Master since she and Toka moved in to their apartment in episode 10
Rikka's Wicked Eye is a reference to these following anime characters' third eyes: Rokudo Mukuro's Six Paths of Reincarnation from Katekyo Hitman Reborn!, Sasuke Uchiha's Sharigan and Neji Hyuuga's Byakugan from Naruto, Hiei's Jagan Eye from Yu Yu Hakusho and Starjun's third eye from toriko
Rikki is the club leader of the Dark magic & sleeping club