I came up with the name myself.

The edge of the endless world... And the color of your name. TN: Yakumo means "eight" or more metaphorically "countless" clouds. Yukari and Sumire are both variations of "violet/purple".

But as of late... I've realized something.

Usami-san. What if your copy...

was actually Renko?

Your doppelganger... I wonder...