RME

Immediate thought is "Signal", crime/thriller with a hint of romance in it, but only a touch. Only problematic thing I can think of is that there might be faster monologues that together with the subtitles might annoy your mom. It's a must watch though.

Another one I heard good talks about is "Voice" but I haven't actually seen that one myself (yet).

Both do feature a supernatural element though, so not sure if it is what you're looking for :/

Ahh damn, the subtitles must be such a pain. Here it's easier as most countries only do subtitles in general, so we're all used to it x)
For me While You Were Sleeping has been a guaranteed success, so if you ever wanna try again :P

Can relate to this. Imo for anime/manga fans it's easier to show them something that has more romance and especially triangle setups, because they're familiar with it (and in drama generally more happens than "I like you" "Oh, I now realise I like you too" *end credits*)

For me a guaranteed success has been "While You Were Sleeping". The reason I always suggest it to people is because it dips into what you describe that crime/thriller is more interesting. It also seems to dip into the cheesiness just the right amount while also just having great humour for everyone.
Also the cinematography is **amazing**, which is an added bonus for my study field :D