I'll cut to the chase: The manga starts off as a sort of fluffy, SOL Romcom thing, and quickly devolves into erotica. At first we have the occasional suggestive shot of Sensei, and by chapter 11 we've literally got her and MC's sister naked in their house, with the two of them inviting him to shower with them. If you're here for innocent ecchi and a cute romance, you're better off going somewhere else, because according to the spoilers I've seen, the characters get dumber, and the scenes more explicit. I don't know what more MAL wants me to tell you when I've already explainedwhat the draw for the series is, and that the author throws it all away in lieu of drawing erotica. I guess I could tell you that she also just wears lingerie around the house (Which MC sees) on her days off because a saleswoman pushed her to buy some and she was too much of a doormat to say no, so now she wears it so she doesn't feel like she wasted money. The story, and characters, are all on this exact level of stupid for the entirety of the series, it seems.