I'm convinced Negi-san has a goddamn crime-scene chalkboard with red-string everywhere connecting all of the girls, Fuutarou, the 6th sister, the family, the injuries, and the goddamn kitchen sink. I've seen easier to follow or solve mysteries in mystery manga. But that's probably because Negi-san can literally change from drawing each character with their unique structure and silhouette into the same carbon copy Itsuki, and that's a pretty unique dilemma.