Welcome to the forums. I'm sorry that you're gotten a diagnosis of PNH. It's important to learn about the disease and its treatment choices.
There is a good summary of PNH treatments at
www.aamds.org/diseases/pnh/treatments.
You can read other information about the disease starting at
www.aamds.org/diseases/pnh.
The PNH treatment drug called eculizumab is available in Japan (see
press release) although I'm not sure if it's approved in Japan for treatment of PNH.