EL James marks Christian Grey's birthday with releases of 'Grey'

Celebrating her fictional hero, Christian Grey's birthday, EL James has released the fourth book in her series of erotic novels.

Grey, which is told from the perspective of the eponymous business tycoon, has been the top Kindle pre-order book of 2015, and became an instant publishing sensation after it's e-book release, reports the Guardian.

The 52-year-old author's fans in Australia, New Zealand and Hong Kong have already branded the book 'perfect' on social media.

*NEW ANIMATED BOOK COVER* Grey: Fifty Shades of Grey as Told by Christian by @E_L_James pic.twitter.com/VLmRGcZ0EH

— Jada D'Lee Designs (@JadaDLee) June 14, 2015

James, who announced the launch of the book in June, claims that she decided to write it after her fans asked her to tell Grey's side of the story of his erotic relationship with virginal college student Anastasia Steele.

The Fifty Shades series tells the story of a dashing 27-year-old self-made billionaire with a troubled past, whose ordered world becomes unsettled when he meets Steele and introduces her to kinky sex, sadomasochism and bondage.