Well, it IS true that there isn't that much time put into build up and introductions of characters other than the main two, but this series feels pretty fast paced and I don't expect it to go on very long (I haven't looked into it's serialization, so please correct me if I'm wrong). I guess it's more about having a twist on the usual tropes (otaku x gyaru, makeover chapter), so I feel like the aim is to hook the reader via big turns every one or two chapters and not through detailed character development like for example Bloom Into You.