Although the GUI doesn't make it very clear, the game supports save slots beyond 8 pages. The amount of saves per page can't be changed, unfortunately.
MORE than 8 pages of Saves? Yeah I had no idea. All games with that save style are set (from the 100s I've enjoyed) and there's nothing to do but over-write unless the creator of that VN releases an Update using the 5 page 30 slot save style. Also, I wonder if you NEED Trust and Corruption on this particular game? Hell. So confusing. Some games you need Trust/Friendship to enable Lust/Corruption sometimes they're mutually exclusive where it's Domination or Friendship not both.