There are several situations in Gyakuten Saiban that are similar to this, but that's a murder mystery series so explaining who and why very quickly gets into super duper spoiler territory.
Shanoa from Castlevania is also fairly similar to this concept but her situation is somewhat complex because the English translation of Order of Ecclesia really emphasizes that aspect of her character in a way that isn't really present in the original. It's a fun game either way so I'd still recommend checking it out.
There are also at least a couple characters like this in the Rance series. セスナ・ベンビール (I have no earthly idea how her name is supposed to be spelled in English) is like a perfect 100% fit for your description; she got hit by some kind of Sleep spell and has been a drowsy Kuudere ever since. Also what you described is fairly similar to the entire plot of Rance II. And Aegis Kalar is an interesting case as well because at one point early on in her game she's tricked into thinking that she's in this exact situation but she actually isn't and is just a normal kuudere who has amnesia. The Rance games have something like a thousand named characters, I might even be missing a few.
I also thought of Quiet from Metal Gear, but she's basically the exact opposite in that she can ONLY express emotions physically.
