From Chibi Manga:

Hanako, who's living in the dormitory for girls, will be in big trouble because the girls dormitory will be combined with boy's dormitory...

But she can't accept that!

From Shoujo Sense:

Hanako doesn't have much experience with boys, so when she finds out Bara High (and its adjoined dormitory too!) is becoming co-ed, she becomes excited. But the first boy she meets is the top student from the boy's school, Kakeru, who turns out to be not as nice as he seems, and declares that he will make Hanako share a room with him! How will Hanako deal with this mess?!