()こう

むこう
noun
over there, opposite side
1. over there, the other side
A place that is across from or on the opposite side from where the speaker is.
Mountains are visible over there.
There's a town on the other side of the river.
Shops are lined up on the other side of the street.
There are foreign countries across the sea. I want to visit someday.
Looking from the window, the mountains over there had turned white. It must have snowed.
2. the opposite party, they
The other side in a negotiation or relationship.
()こう()
To ask them (the other party).
We received a phone call from them (the other party).
To talk with the other company.
They haven't said anything about this issue.
Since they're in the wrong, I don't think we need to say anything from our side.

()こう indicates a place across from or opposite the speaker's position. It implies there's something (like a road, river, or distance) between the speaker and that place. [noun]()こう means 'on the other side of [noun].' It can also refer to 'them' or 'the other party' in business or relationship contexts.