adellace said:recently I cant even view the page of the website.
This is easy to troubleshoot. I am assuming you're using windows, if you don't, or if you got particular questions about steps, just use effing google.
1) nslookup chan.sankakucomplex.com in CMD (up to W7) or anything equivalent that uses DNS as available to your device. Note if it resolves to IP, and note the IP.
2) tracert.com/resolver or any other public resolver to see tho correct IP.
3) If you got 2x same IP, the problem is with your device. Go format C or something (...you can try flushing DNS and a cold reset first though)
4) If you can't get the name resolved locally, it's likely a problem with DNS of your ISP - can be bugged, or they can be blackholing the site.
If it's a bug, it could go back to normal in a day or two.
If it's deliberate, you can simply force your system to use Google DNS or OpenDNS instead whatever politically correct shit your ISP is forcing down your throat... if they aren't blocking those on routing tables, that is.
Alternatively, at least up to W7 you can edit your hosts file to manually force the site domain name to resolve to the correct IP.