In Chapter 12, Zange offhandedly remarks to Watanuki that the path he takes will be decided in 2 days. Then in Chapter 15, believably about 2 days later, Karuta gets attacked and seriously injured, starting a series of events that decidedly impact everyone's paths and the plot itself.
After hearing about Ririchiyo's past, it's no wonder that she was immediately averse to Soushi. She's spent her whole life getting special treatment from people who couldn't care less about her, all because of a family who treated her like a lucky charm and openly preferred her little sister. Even when she moves into a new place in order to have a new stigma-free life, she discovers that they've hired a secret service agent against her wishes, and he's basically all of her issues with her past relationships up to eleven. Soushi is the personification of literally everything she hates about her life.
When you consider that Zange's power lets him see into the future and into his past incarnations, his life is pretty much a single long, endless loop of meeting friends who don't remember him only to watch them die in the same way over and over again.
Not only that, but it's implied that using the full extent of his power too much dooms him to an early grave and that it's happened multiple times before, meaning he not only knows when he's going to die, but also continues to sacrifice his health for his friends and simply forces himself to live with it.
