Please and thank-you. :-)

At the bottom of the picture it's written: illustration, unmei no kagi akemasu.

Check the lower left corner, it reads there. (≧∀≦)

Illustration from Ajimine Sakufu.

Lol Yeah, now I feel like an idiot... Thanks, guys. lol X-D

It's novel, Unmei no Kagi Akemasu by Itsuki Ioka, Sakufu Ajimine.
http://www.zerochan.net/Unmei+no+Kagi+Akemasu

Thank-you. :-)