TTIBAS Part 5 Second Half - Update 13/05 (Pixiv Fanbox)

Here's the next update of TTIBAS! Something's wrong with Yuuki... could it be the crest she has on her crotch? What does that crest do? Does it only increases Yuuki's arousal or... no it can't be... We'll have to wait until next update to know what happens! Or at least have a hint of what could happen!