The problem with this manga is that it recycles material. Premise, jokes, and plot points. What could be written in 7 chapters, took three times that. Like the story pointed out, the characters are "just a tool to move the story forward," but even that is done a snail's pace. This is why Double Peace and Mai suffer badly in the character department. They repeat phrases like Pokemon and aren't interesting because of that. There's no fun in guessing what they say and their routines become repetitive fast. The MC and sister manage to be the better written characters just by comparison alone, despite also suffering the same.