That was cute, I have to say. Maybe Yuriko's desire to learn and solve mysteries is partially due to being afraid of the unknown and unexplainable. It would be a fare more proactive way of dealing with it that trying to ignore and avoid it at all cost.
@Say I see, Himawari first mentioned her back in chap 3 and the hair color matches the one in the cover of vol 6.. anyway thanks again for the chapter.
After jumping back to ch15, to check the ghost episode, I realised we are seeing quite less of senpai's heart pupils in the later volumes. Character progression?