When you play V0.29 if you manage to get Tsuyu to join your team for the cave mission you can indicate how you did it because some of us can't do it
READ THE LAST 3 SENTENCES FIRST!!!
Good news!!! I've successfully found a way to recruit Tsuyu in cave exploration!!! Google Drive with the files inside dowload both the files. Now, after downloading, search Renpy Repack then submit the downloaded "2-1-LT1" below that you will need to submit the "security_keys.txt" which you can find in your save folder of the game then click "repack and download". After that, you will have "2-1-LT1-1" in which after you obtained you will need to delete the original 2-1-LT1 and rename the "2-1-LT1-1" to "2-1-LT1". Lastly, you will need to insert the new 2-1-LT1 and the "persistent" files inside your save folder of the game then launch the game and click "Load" and then you can find the new save file in page 2 of the "Load" page.
WARNING!!! YOUR PREVIOUS SAVES MIGHT GET CORRUPTED BECAUSE YOU CHANGED THE PERSISTENT FILE, I RECOMMEND FOR YOU TO CREATE A BACKUP OR CONTINUE THE NEW SAVE FILE!!!!!!
Ps. This is the "Join her" route.
Ps. I saved this from 0.27 so you might need to play more onwards