袂を分かつ Can someone explain this expression?

Question

I was reading a light novel and I looked up the meaning of 袂を分かつ, but I wonder, can someone explain this expression in more detail as to why it means break off relations with/part with someone?
Tamoto (袂)is part of the kimono sleeve, so taken literally as 'cutting the sleeve' how does it relate to cutting of a relationship?

Answer 1

There is a useful explanation of this phrase at this link here.

A quick summary is as follows:

The 袂 (たもと) is a part of the sleeve of the kimono which hangs down to the side, sometimes even stretching below the hands. In fact, the word たもと appears to be a variant of 手元 (てもと). As such, the word took on the additional meaning of 'beside', 'next to' (see definition), since it hung down to the side of the body.

The word 分かつ has the same standard meanings of 分ける, i.e. 'to divide', 'to separate', etc (see definition).

So the phrase 袂を分かつ took on the figurative meaning of 'separating from what is next to you'. In other words, to break off a connection with someone who used to be close to you. It seems to apply more to non-romantic relationships, such as a friendship which has soured or a working relationship with a colleague which has become strained. The examples listed are:

この間、ついに大喧嘩してしまい、袂を分かつことになった。

and

そろそろその人とは、袂を分かつときが来たのかなと感じている。

And by the way, please don't confuse it with トマトを分かつ.
(That was my attempt at a joke).