I tried a few searches but maybe I'm not using the right tags or something cause I've had no luck.

From what I recall, the male lead is blind and fights in some way (with a sword?). He is working with an organization that either gave him some form of echolocation gear or he has honed it himself. He is met by a young girl who he needs to protect, she claims to be a psychic and that in the future they will get married. It's a modern setting, with cars and tech items.

I read the scanlations quite a number of years ago, no idea if they were ever finished.

Shi ga Futari o Wakatsu Made

~4400 manga completed
~1700 ongoing...

That's the one! Thank you so much!
I had seen the cover when searching before, but must have misunderstood what I was seeing cause it didn't look at all what I was expecting, so I had skipped it over accidentally early on. 😳