At the beginning of the story Ido gives us the impression that he has gone back in time, and regretting his previous actions is trying to redeem himself. I think it was his fault that Sejin killed himself.
I'm a massive fan of hers! I love Dokyuusei, Double Mint and Inheritance of Aroma! Her, Scarlet Beriko, Nishida Higashi, Zariya Ranmaru and Ogawa Chise are some of my favorites mangaka!
Chapter 150... ╥﹏╥