(kananime.zone) ANIMANGA/LN/WN Raw Link

                
Thanks to @isecai for summary, although he wasn't particularly online since 2018. https://www.novelupdatesforum.com/threads/other-jp-wn-source-besides-syosetu-and-alphapolis.68931/
Web Novels
https://ncode.syosetu.com/ (Syosetu, free)
https://mnlt.syosetu.com/ (Moonlight, dark side of syosetu, Josei and BL)
https://noc.syosetu.com/ (Nocturne, dark side of syosetu, ecchi/R18)
https://alphapolis.co.jp (free and paid, also has niche manga)
https://www.pixiv.net/novel/ (free, fanfic and original)
https://syosetu.org/ (Hameln, free, mostly fanfic with originals)
https://kakuyomu.jp (much like syosetu but with contests, free, some titles are crossposted, more individualized reading experience)
https://novel.comico.jp (WN with illust, free and paid, has webcomics)
Light Novels (teasers)
https://alphapolis.co.jp (Rent with coins--Paypal OK, LN in WN format)
https://over-lap.co.jp (Samples only, buy in outside shops)
https://bookwalker.jp/st1/ (Samples, buy with Paypal/CC, open in their own desktop/browser apps)
Cellphone WN
https://novel.maho.jp/ (most populated I think)
http://potal.0zero.jp/novel/ (I can't open this one yet)
https://www.no-ichigo.jp/ (cutest looking)
http://book.xmbs.jp/ (plain?)
General
https://estar.jp/ (short WN, more friendly for non-isekai stuffs lol)
https://www.magnet-novels.com/ (WN contest and the entries are in satisfying amount smh)
https://pkcr.jp/ (short/cellphone WN, split into General and BL lol. More modern looking site)
http://www.raitonoveru.jp/index.htm (seems a bit desolate, but it has many titles already, they dedicated a page for titles published in amazon up to 2013)
http://slib.net/ (veeeery modern and clean. More novels than WN/LN)
https://www.berrys-cafe.jp/pc/ (female oriented, looks sweet and active)
https://www.akatsuki-novels.com/ (fanfics only(?), but with "OC MC" tag hahaha)
http://www.kakiko.cc/ (interesting, the novels are posted in forum thread format. The read between part is seamless though, it's enabling the authors to add in bite-sized chunks. Pretty sure not all cellphone WN are formatted like this...)
http://taskey.me/stories (beta version, slow loading. Cookie point: readers can translate the works and it'll be posted right under the title. It doesn't seem to be populated recently though---not since 2015)
http://www.novepro.jp/ (the entries are displayed in book pages.)
https://d-love.net/ (more girls oriented, a bit desolate. Maybe more like a closed community)
http://hoshi-suna.jp/ (cellphone WN, definitely. Hard to navigate from PC)
LN teasers
https://booklive.jp (samples. Much like bookwalker, but can't accept Paypal (CC OK tho). Has more extensive categories---novels, not just LN)
http://cobalt.shueisha.co.jp (samples. Only for shueisha publisher. Previews are lighter to load than bookwalker/booklive though.)
BL only
https://fujossy.jp/ (also has manga and other goods category)
http://id.fm-p.jp/ (cellphone WN, navigation is a bit hard to find tbh, mostly josei and BL)
http://blove.jp/index/detail/ctype/novel/stype/updated (more illust friendly than syosetu at a glance WN)
http://bl-novel.jp/ (short WN, split into original and fanfic)