This manga is very specific in that it focuses heavily on suicide. I don't recommend this manga to lighthearted people.

If you only have read up to chapter 17 then i recommend to read the raws that were not translated even if you can't read Japanese. But to sum up the last few chapters Kaede kills her father then commits suicide for jumping from a high building. And Kaname and Shiina were going to commit suicide but stop and Shiina was hospitalized. Then theres a time skip where Shiina is less fixiated on death and Kaname is mourning Kaede's death.