New character "routes" (potentially the "Bamboo" area or character). New dialogue trees and "branching events".
: Integration of new quests and identity-altering events. The Isle Of TS Monster Girls -v1.3- -Bamboo Sho... UPD
For a deep dive into the mechanics and specific changes in v1.3, you can check out video essays and reviews from creators like Rough Edge who specialize in RPG Maker titles. I Reject My Humanity, Jojo! - The Isle of TS Monster Girls New character "routes" (potentially the "Bamboo" area or