obanai felt as he shouldn't have been born in this world. he felt impure and had lost all will to live. but when he met mitsuri, he wanted to change so he can become a man who can stand beside her. to do good deeds to become "good." all of this was done for his pure love for her
sanekana is an absolutely amazing ship. sanemi admiring kanae for who she is but also loving the relationship of her and shinobu. him also wishing for a relationship like that with genya making him love her and her efforts even more.