Blue Sky Complex

Motochika Narasaki comes from a large, noisy family, and his two little brothers make it nearly impossible for him to have any alone time. When his need for peace and quiet coincides with his teacher arm-twisting him into minding the school library in the evenings, he hesitantly accepts. What he does not expect, though, is running into the infamous delinquent, Natsuki Terashima, who has been roped into taking care of the library as well. Initially Narasaki is convinced that he could never get along with someone like Terashima; however, as he spends evening after calm evening reading with the other boy, Narasaki is forced to change his opinion, and the odd pair gradually become closer. But this arrangement will only last till the summer vacation, and Narasaki must soon figure out what this time, and the person he spends it with, mean to him.

(Source: MAL Rewrite)