A single lock of hair sticking up out of a person’s head. When planning the characters, we felt that compared to the twin-tailed Girl A (placeholder name), Girl B’s (placeholder name) character traits couldn’t keep up so we stuck on an ahoge (radio antenna?). Typically, mostly our leading characters like Saber and Arcueid sported ahoge, but recently ahoge are showing up more and more, maybe it is infectious.

HibiChika Complete Capture Book: Mahou Tsukai no Hako Small Encylopedia