From Senpai Scans:

Let us search for fellow youthful club members for our mysterious club activities!
Because of her father's adventures, Miku is entering school 3 months late. As such, she's petrified of being excluded and not having friends. He, the school special's extracurricular "finder", gave Miku an opportunity to make friends. And thus, somehow, Miku managed to join a club...