https://www.resetera.com/threads/guide-to-installing-%E2%80%9Cyou-and-me-and-her%E2%80%9D-on-steam-deck-proton-tricks-protonge-explained.922233/

Can launch and play the game right after installation. Just that the dialogue and the background music are not available. After installing xact using Proton tricks, the game will behave normally with all the sounds. The steps are as follow, thanks @Jawmuncher

1. Install the game.
2. Go to desktop mode and search for "ProtonTricks" in the Discover App. Install and launch it.
3. It may prompt you to execute a command if you have a SD card inserted. Execute the command and restart it. This will give ProtonTricks permission to read / write to the card.
4. Select the game name from the list, in this case, "The Quintessential Quintuplets - Five Memories Spent With You".
5. Select the default Wine prefix.
6. Select "install a windows DLL or component"
7. Find XACT (not the 64 bit) and install it.
8. Go back to game mode.
9. (Optional) Set the launch options "PROTON_NO_ESYNC=1 %command%", not really needed I think.
10. Enjoy the game.