Dansho no Grimm X Ibara-hime (Part 1)

is the tenth volume of the Dansho no Grimm light novel series, written by Gakuto Coda and Illustrated by Mikazuki Kakeru. It was released under the Dengeki Bunko Imprint in April 2009.

Synopsis
Aoi plans to stay with Yukino for as long as possible after the summer vacation begins. However, Yukino and Sohime, who went to solve the bubble, did not come back. Yukino and his friends seem to be trapped in the Makita family against a heretic who never dies. The mansion was completely isolated from the outside world due to an abnormal phenomenon. It was Aoi who went to the residence alone for Yukino.

(source: Bookwalker JP - Translated)