Shounen AR

Yanagitaka Chiho is a librarian, but he doesn't work for your local branch. He works for the Misukatonniku Library, which is rumored to contain the world's history and knowledge and will grant your wish without collecting payment. However, you must obey the contract and heed the due date. If not, Chiho will hunt you down and collect more than just a small fee.
(Source: shinkeikaku)