As you can see, Incest Mania series starred Toshi & Tomoya Kikuchi. They are now a famous gay couple in JGV. Though, their films seems to be very rare when you want to download for free. Luckily, I found some links that are pretty easy for you to get their films.
These links are for Incest Mania 1, you can download them one by one or at the same time, because this host doesn’t limit downloaded files. You just have to type the capcha and download with IDM.
Here are the links: