diff --git a/README.rst b/README.rst
index 8e9d6581..3249d569 100644
--- a/README.rst
+++ b/README.rst
@@ -124,11 +124,11 @@ Download images; in this case from danbooru via tag search for 'bonocho':
     $ gallery-dl "https://danbooru.donmai.us/posts?tags=bonocho"
 
 
-Get the direct URL of an image from a site that requires authentication:
+Get the direct URL of an image from a site supporting authentication with username & password:
 
 .. code:: bash
 
-    $ gallery-dl -g -u "<username>" -p "<password>" "https://seiga.nicovideo.jp/seiga/im3211703"
+    $ gallery-dl -g -u "<username>" -p "<password>" "https://twitter.com/i/web/status/604341487988576256"
 
 
 Filter manga chapters by language and chapter number:
@@ -199,7 +199,7 @@ Username & Password
 
 Some extractors require you to provide valid login credentials in the form of
 a username & password pair. This is necessary for
-``nijie`` and ``seiga``
+``nijie``
 and optional for
 ``aryion``,
 ``danbooru``,
@@ -225,7 +225,7 @@ You can set the necessary information in your configuration file
 
     {
         "extractor": {
-            "seiga": {
+            "twitter": {
                 "username": "<username>",
                 "password": "<password>"
             }
diff --git a/docs/configuration.rst b/docs/configuration.rst
index d4fadf7e..31ca72df 100644
--- a/docs/configuration.rst
+++ b/docs/configuration.rst
@@ -356,7 +356,6 @@ Description
     Specifying a username and password is required for
 
     * ``nijie``
-    * ``seiga``
 
     and optional for
 
diff --git a/docs/supportedsites.md b/docs/supportedsites.md
index 31388824..e2d6e416 100644
--- a/docs/supportedsites.md
+++ b/docs/supportedsites.md
@@ -521,7 +521,7 @@ Consider all sites to be NSFW unless otherwise known.
     <td>Niconico Seiga</td>
     <td>https://seiga.nicovideo.jp/</td>
     <td>individual Images, User Profiles</td>
-    <td>Required</td>
+    <td><a href="https://github.com/mikf/gallery-dl#cookies">Cookies</a></td>
 </tr>
 <tr>
     <td>nijie</td>
diff --git a/gallery_dl/extractor/seiga.py b/gallery_dl/extractor/seiga.py
index bf38a772..22c94870 100644
--- a/gallery_dl/extractor/seiga.py
+++ b/gallery_dl/extractor/seiga.py
@@ -1,16 +1,15 @@
 # -*- coding: utf-8 -*-
 
-# Copyright 2016-2020 Mike Fährmann
+# Copyright 2016-2022 Mike Fährmann
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License version 2 as
 # published by the Free Software Foundation.
 
-"""Extract images from https://seiga.nicovideo.jp/"""
+"""Extractors for https://seiga.nicovideo.jp/"""
 
 from .common import Extractor, Message
 from .. import text, util, exception
-from ..cache import cache
 
 
 class SeigaExtractor(Extractor):
@@ -25,7 +24,9 @@ class SeigaExtractor(Extractor):
         self.start_image = 0
 
     def items(self):
-        self.login()
+        if not self._check_cookies(("user_session",)):
+            raise exception.StopExtraction("'user_session' cookie required")
+
         images = iter(self.get_images())
         data = next(images)
 
@@ -45,28 +46,6 @@ class SeigaExtractor(Extractor):
             url, method="HEAD", allow_redirects=False, notfound="image")
         return response.headers["Location"].replace("/o/", "/priv/", 1)
 
-    def login(self):
-        """Login and set necessary cookies"""
-        if not self._check_cookies(("user_session",)):
-            username, password = self._get_auth_info()
-            self._update_cookies(self._login_impl(username, password))
-
-    @cache(maxage=7*24*3600, keyarg=1)
-    def _login_impl(self, username, password):
-        if not username or not password:
-            raise exception.AuthenticationError(
-                "Username and password required")
-
-        self.log.info("Logging in as %s", username)
-        url = "https://account.nicovideo.jp/api/v1/login"
-        data = {"mail_tel": username, "password": password}
-
-        self.request(url, method="POST", data=data)
-        if "user_session" not in self.session.cookies:
-            raise exception.AuthenticationError()
-        del self.session.cookies["nicosid"]
-        return self.session.cookies
-
 
 class SeigaUserExtractor(SeigaExtractor):
     """Extractor for images of a user from seiga.nicovideo.jp"""
diff --git a/scripts/supportedsites.py b/scripts/supportedsites.py
index 3fe86752..d2df6bb3 100755
--- a/scripts/supportedsites.py
+++ b/scripts/supportedsites.py
@@ -265,7 +265,7 @@ AUTH_MAP = {
     "ponybooru"      : "API Key",
     "reddit"         : _OAUTH,
     "sankaku"        : "Supported",
-    "seiga"          : "Required",
+    "seiga"          : _COOKIES,
     "seisoparty"     : "Supported",
     "smugmug"        : _OAUTH,
     "subscribestar"  : "Supported",