Back in the day, you had so much filler, you could make a whole new show out of it. Nowdays they cut so much stuff from mangas, it changes the entire context of the story. Recently I finished 5Toubun anime, and it was ok, but felt like stuff is missing. So I started reading manga and yup. The entire Rena subplot makes so much more sense now, and now it finally feels like Yotsuba is part of the race, rather than just poping into prominence at random. Also Nino is even better character than before. Why they do this?