Hi. +1 from me on how usefull your flowchart is, triple so because the player can use it to jump to the chat through it. It's a perfect in-game guide!
If I may make a suggestion, though, currently there are no indications or hints of how the player can access it, so I'd reccommend either a message informing the player when entering the chat, or a button maybe next to or on the other side of the picture of the girl the player is chatting with.
Looking forward for future updates!