Is it okay to use another player's character 'fantasia' as your own without asking?

[Mikki]

All the characters in this game look the same anyway. Who cares? pfft. 4 face options and a handful of hairs. If you're gonna be upset that someone else looks like you, this isn't the game for you.

In fact, my character used to look exactly like OP's years ago. Omg, did you take my fantasia????? How dare you.

[MsQi]

I find doppelgangers all the time.

I don't seem to have that problem.

[Yuki_Lowell]

I don't seem to have that problem.

And we can guess why.