(lol sorry if im replying months late, i just finished reading this masterpiece)
I also have the same question, like why did Midori prevent Sho from going outside? Is it because she wanted Sho to live like Ao? Cause Ao was imprisoned and isolated as well, but it doesn't make sense if Midori wanted to break free away from the Hasegawa family, cause she's doing the same thing to Sho as what they did (tho she's less harsh and a little more humane)
As for Yonghyun being chosen as the one to inherit from the start, I am not 100% sure but I think Midori wanted Sho to have someone as a friend at first. Because spirits like them get lonely so they find a human to be with them. Since Sho got attached to Yonghyun, maybe Midori got the idea to make him the successor, but Yonghyun still needed to pass some sort of test, and their escape was the test itself.
As for Itami (the old man), I believe that Midori didn't kill him exactly, but he volunteered to offer his life (in ch 61). As per the Hasegawa tradition, they needed a sacrifice to transfer the ownership from Midori to Yonghyun. That ritual has been followed closely through generations in the family. Since Midori does not want to do the rule of the successor killing the predecessor, Itami offered his life instead.
Though Midori theorized that maybe they didn't need to do all that since the pledge that Yonghyun made with Sho was not because of the Hasegawa tradition so they didn't need to follow their process to transfer the oath. Sho was a new spirit and Yonghyun was the first to make a pledge with him so their contract was something different.
Feel free to correct me, but that's what I understood from the story
Thanks for the reply! I love characters like Midori who’s portrayed as the ”villan” at the start who you think nothing could ever make you like them but then you get their backstory and understand them better. I think we were all rooting for her in the end, I’m still not completely sure why she needed Ao to live isolated to the extent he did (not even being allowed to look out a window). The whole sect thing with the meeting was really creepy. A lot of confusion is probably due to the magical uncanny touch that the story has where some things will always remain a mystery. I forgot about the need of a sacrifice, thank you for pointing that out it makes a lot of sense. I’ve found a stronger sense of closure regarding this work just by time passing and I hope you do to! Overall a very good story where you dive in way deeper than you can even imagine when you start reading it.
*Sho not Ao
This was sooool good, incredible. I was honestly prepared for a sad ending so the ending was really comforting. One thing I didn’t really underhand is why Sho was locked up, he needed treatments but why was even looking out a window not allowed? I know Midori said it was to protect him, but I didn’t really catch up on what her plan for him was. To just live there forever? To become her successor (which seems contrary to what’s revealed about her last)? I know she planned for Yonghyun to inherit everything, was that planned from the very beginning and the sole reason why he was chosen as the friend? Also, why did she have to kill that old man instead of just letting him quit and live out his last years in peace? For Sho it was a test, but I don’t think that was the case for the old man.