We are all on two XP.
Your PC is on three XP.
If you fill in with a different character for one scenario then we will all be on three XP together.
It's not a big deal, just an idle thought.
That isn't what I meant.
You have two xp, so if my one xp character completes an adventure to become two xp, then you all would have completed an adventure and become three xp.
Basically, you all will be perpetually either one xp ahead of Lady Yumiki, or one xp behind Naomi.
If I had a gm that was faster or slower than yours, eventually the difference could be caught up, but that would require a couple adventures (I doubt either side will play adventures twice as fast as the other), thus by that time, the empty slot will have been filled.