For several episodes, the openings have been hinting that there would be a couple of important, recurring characters.
I won’t spoil it. Go and watch the episode for yourself.
It looks like the show is finally moving toward some actual character development……..
For 60 episodes, Rinne has been mostly stuck in a rut. He got a tiny bit of character development in the course of his romance with Mamiya Sakura. The opening and ending show them acting a little more rovu-rovu, so we might be getting close to the end of the story. Although Mamiya is somewhat cold and lacking in romantic openness, there have been enough hints that she would commit to Rinne if he could get his life together. I suspect that Rinne will grow enough to solve his own problems, and then Mamiya will choose that moment to commit to him.