What You Learn Today Can Be Overturned Tomorrow

Haruto watches as his younger sister, Mikoto, seems to blithely accept the reality of figurines that move on their own, but Mikoto actually wants to unravel the mystery of the phenomenon and presses Nona for answers. Haruto, on the other hand, wants to have fun with his otaku buddy Kanmuri Seijirou in their otaku discussion, but...

Synopsis excerpt via Kitsu.