There are 3 repositories under koikatsu-party topic.
Mod, plugin and card manager for games by Illusion that use BepInEx
Various plugins for various Illusion games
Plugin pack for exporting Koikatsu characters to Blender.
Support for interactive sex toys in over 20 different Hentai games, including Koikatsu, Honey Select 2, COM3D2, Insult Order, and more.
A collection of fixes for common issues found in games by Illusion
English Launchers for games made by Illusion Soft
check and move/convert KKS card to a new folder
Plugin for quickly searching through studio items in games by Illusion
English-language translation of the Illusion eroge Koikatsu (images only)
Koikatsu Auto File I/O. Create backup, filter and convert kks cards, install/remove chara given a folder.
A plugin that allows you to change the generic cutscene mobs in Koikatsu