Spoiler Alert: The following article has information not currently present in the anime or manga. Do not proceed unless you want to be spoiled.
[Gallery] Leen ( リーン Rīn ) ?
is one of
. She was the tribal chief of the fairy tribe
before becoming the court magician of
Brunhild Dukedom 
. She currently lives with Touya and
Leen's daily attire.
Leen in her swimsuit.
Leen is shown as a young woman despite her age, with silver twin-tails and gold eyes. She is usually wearing a lolita dress.
She has a strong thirst for knowledge. This can be seen in her enthusiasm for discovering all 9 Babylon flying structures.
: this magic allows Leen to set rules toward inanimate objects which is similar with the computer programming. This magic can be added into the same object infinitely.
【 Program】 : this magic allows Leen to transfer her Mana to the appointed receptor.
【 Transfer】 : this magic allows Leen to protect certain inanimate objects from physical degradation and prolongs its lifetime.
【 Protection】 : this magic allows Leen to find the intended object only based on the exact parameter. Based on the certainty principle, her magic can not be used to find a slightly different object.
【 Discovery】 Appraisal ( - As a "FAMILY" 鑑定 Kantei ) ? ( of 眷属 Kenzoku ) ? Touya Mochizuki, her magical item appraisal ability is sharpen and becoming her "FAMILY TRAIT" (. 眷属特性 Kenzoku Tokusei ) ? .
Grimgerde - Leen's exclusive  Frame Gears which is a blitzkrieg assault type FG.
Sacred Ring - Leen received platinum gold ring from  World God as wedding gift which was given through the great spirits. The ring is a sacred treasure which can act as receiver for Touya's divine power.
"I can not believe this thing is actually happen in my live. That's what a longevity can do, huh?" - Leen before her wedding kiss .
Web Novel Arc 18 Chapter #134, Leen told Touya about her age.
Web Novel Arc 29 Chapter #405, It has been two years since Touya met her. ↑
Web Novel Arc 6 Chapter #45, Touya described her appearance as a girl with white hair and gold colored eyes.
Web Novel Arc 22 Chapter #185, Leen has all magic affinity except Dark.
Web Novel Arc 6 Chapter #45, Leen showed her program null magic.
Web Novel Arc 5 Chapter #32, Touya learned transfer, a null magic that have been taught by Charlotte's master, Leen.
Web Novel Arc 6 Chapter #48, Leen told Touya about her protection null magic.
Web Novel Arc 24 Chapter #232, Leen told Touya about her discovery null magic. ↑
Web Novel Arc 31 Chapter #448, Leen married to Touya. ↑
Web Novel Arc 6 Chapter #45, Leen introduced herself as the chief of fairy tribe. ↑
Web Novel Arc 22 Chapter #184, Leen retired as the chief of fairy tribe.
Web Novel Arc 29 Chapter #389, Leen was the Mismede's court magician.
Web Novel Arc 7 Chapter #54, Leen decided to stay at Kingdom of Belfast as an ambassador.
Web Novel Arc 14 Chapter #103, Leen decided to stay at Brunhild Dukedom as an ambassador. ↑
Web Novel Arc 22 Chapter #184, Leen decided to become Brunhild's court magician.
↑ Web Novel Chapter 30 #442
Web Novel Arc 26 Chapter #255.
Web Novel Arc 31 Chapter #449. ↑
Web Novel Arc 31 Chapter #449.