Kijou Eri to Hiiro no Meikyu: Eikoku-tei Gensou Jiken File

is a Japanese light novel series written by Akizuki Okawa, with illustrations by Yasuyuki. The series began publication on April 10, 2008 by ASCII Media Works under their Dengeki Bunko publishing imprint.

Synopsis
"If you want to live, I'll help you." I am a sophomore in high school who was involved in a serial murder that shook Tokyo in the middle of winter. It was Eri Kijo, a beautiful girl who was irreverent and self-respecting, but had a mysterious charm, that I entrusted her life to. Eri, who holds a PhD at the age of 18, set up an office on the second floor of an old coffee shop "British Tei" and lived with a self-proclaimed maid Aoi and a young girl Rin with silver hair. And it is said that the existence of "EVE" that she is pursuing is related to the serial murder case ...!?

A mystery about the beautiful girl scholar Eri and me appears.