Might be a bit of a hard one.
Backround: They have a bit of stuff on rule34 but I can't find any of the exclusive stuff they post on Gumroad or Patreon. (I.e, stories, exclusive folders with tons of images, ect)
Ohshinakai on patreon and gumroad, links as follow:
Gumroad...
I don't know if this is the right place for a rule34 request but. This one is extremely weird there is only one thing you can get his stuff from and it's only one 385 yen pack. It's well drawn too. I was going to buy it myself but paypal fucked me over. I Would love it if someone can help me out...