18+ Gakuto no Vector

A classmate learns that Minazu Aruto loves reading novels and short stories so she recommends a club that the school has called the Philosophia. The classmate doesn’t really know what the club is about but the name sparks a curiosity in Aruto and he decides to find out what it is. He goes to the old library on campus where he meets and is introduced to all three members of the group: Tomoe, Takaho and Kaede. Without really being explained what the Philosophia club is about, Aruto finds himself joining what he thinks is a literature club.

(Source: MangaHelpers)