@AmiiboPuff I was wondering the same. She mentioned in chapter 1 (https://mangadex.org/chapter/717859/9) that the lives right next-door, so my understanding is that she should be in the bottom-left corner of that chart. That being said, maybe there are more buildings not shown on that chart? There's also the chapter where he visits her apartment, there might be some clue there
@AmiiboPuff
she's on landlady's room, I think it's separate from the other room blocks
basically they all on an apartments block with 3 rooms each floor, she's on different building right beside it