Looking for logging into the Nicovideo Jp site and are not getting the correct working link for it? In such a case, you can use the links given here by searching your desired login page in the search box. If the page is present on our website then you will get all the links related to the Nicovideo Jp site. After that you can login as usual with your login credentials.
https://account.nicovideo.jp/login
http://blog.nicovideo.jp/niconews/63867.html
https://qiita.com/tor4kichi/items/74939b49954d3e72d789
https://qiita.com/ingen084/items/fe43661c877f58df069d
https://qiita.com/59naga/items/0a22e30f019aaef683e4
https://qiita.com/iedred7584/items/b1fbd4f61694696e90be
https://qiita.com/katabamisan/items/8028584b2b6224ce0c92
http://yuinore.net/2017/09/niconico-login/
https://secure.sakura.ad.jp/rscontrol/
https://pronama.jp/2015/06/14/niconico-login/
https://github.com/SSW-SCIENTIFIC/nicovideo-api-nodejs-client/wiki/nicovideo.jp%E3%81%AEAPI%E3%81%AB%E3%81%A4%E3%81%84%E3%81%A6
https://play.google.com/store/apps/details?id=jp.co.dwango.nicoch&hl=en_US
http://b.hatena.ne.jp/entry/s/account.nicovideo.jp/login?next_url=%2Fuser%2F36989604&site=niconico&time=1515034746&hash_key=b973ed68