hey so how do you get the grace scene
One technically isn't a Grace scene, the other is the swim competition. I am unsure of all the triggers outside of just increasing their uh... affection value? W/e it is in this one. The one that technically isn't a Grace scene is during the dream sequence before you do the Cadence intro event. She demands you go to the gym while you are sleeping and having a very lewd dream.
I guess I should also add that the 2nd Grace scene is basically doing all the chain of events during the swim competition. After doing a few of the steps, MC will think to cast a calming spell on Grace, which has some... interesting side effects? Trying to be vague about it. If you want the exacts, I'd have to go back through to remember the steps. Basically just do the explore option a lot to get the other options going, iirc you get it after using the oil on Meryl.