What are the fundamental differences between the ～と一緒に and the ～とともに fragments?
I'm accustomed to saying `together with` using the `~ to issho ni` fragment, but I've been noticing that some people I talk to phrase this using `~ totomo ni` instead. i.e. 彼女と一緒に日本へ来た。 Kanojo to issho ni Nihon e kita. and 彼女とともに日本へきた。 Kanojo totomo ni Nihon e kita. seem to be fundamentally equivalent. Are there any nuances that the two have that dictates when and where they should be used? Probably very slight meaning deviations? Or are they essentially perfect equivalents of each other when it comes to saying `together with` (and yeah, I'm aware that `~ totomo ni` has other meanings aside from that)?