The conflict of the game is around the cursed ring, yes, the title of the game.
If you read the prologue, the ring will say something about the wearer's consequences.
It's a bit spoiler, the player needs to do something to unlift the curse. If you happen to see one of the vanilla scene's mini-game, you will notice there's a selection choice for curse level (The curse level will be implented in the future version.). The curse level determines how strong you can tolerate the stimulation. (This is for future content; the size of the penis will be restored if the curse level reaches zero.)
If the girl hasn't fallen for the rival, the girls won't make fun of MC's size.
Thank you for playing the game and writing your thoughts!