Toggle the invisible state of a character in Studio by clicking Anim->Current State->Invisible Body.

Toggle the invisible state in the character maker to play the main game with invisible characters as well.

Requirements:
BepisPlugins
Illusion Modding API 

Installation:
Extract the .zip to your game folder

Download:
AI version for AI Girl, KK version for Koikatsu, EC version for EmotionCreators, HS2 version for HoneySelect2