How interesting that the writer's discussion about a woman murderer led us readers directly to the impression that she's dragging around a body in her suitcase. However, since we never see the supposed corpse, and her apartment is full of clutter, and the dating app guy comments on her changed vibe, I suspect that the corpse she's referring to is herself, and that she's fallen into some kind of depression.
On the other hand, it wouldn't be much of a Yamashita story if there wasn't some weird murder, so it can go either way and I'll be happy.