Aharen-san is Indecipherable

Short, quiet Reina Aharen sits next to Raidō in class. Aharen is not so good at gauging the distance between people (or personal boundaries), and Raidō initially sensed some distance between the two of them. Then one day, when Raidō picked up the eraser that Aharen had dropped, the distance between them suddenly became uncomfortably close. From "way too distant" to "way too close," Aharen is simply unpredictable.

Source: Anime News Network Encyclopedia