How does Graze actually work?

[C-man]

I can see there are i-frame while Graze activating sometime but I dont really understand how to trigger them

[Oguzhan]

Well I haven't looked into the exact details but from my experience of this game and general touhou, it works like this.

Your hit box is smaller than your sprite. So if your sprite touches an enemy but not your hit box then you graze. Time stop has a MUCH bigger graze box though.