It has 53 full chapters, I don't know how Ganma counts, but they are probably considering the extra chapters, but I don't think we have 12 extra chapters here on mangadex? Not sure though.
Before the confession she was like "let's take a bath together as we did before," but now we get a lore that they only bathed together once?
How did she get to bathe with him anyway? Were they neighbours from the start? Why would his mum be okay with him going to his house and bathing with a...