ranking up isn't really explained, i only learned what it was once i ran into Milki and got the cursed ring rank up, before the game crashed when i lost and got home
Viewing post in Yuki Pop Repeat~ (Ver 0.1.6) comments
It seems sometimes when you go back to "home", any next click will crash the game randomly. I posted bug report about that bit ago.
It's early preview, so hopefully will get patched.
Even if you save/quit normally, inventory items aren't saved ; when next you reopen they will be gone. Unsure if bug or intended.