I just posted this cel the other day to be ID,
and now I get to post it again.  This is from
Tenshi ni Narumon and is of Sara and Yuusuke.
Now I have to go find this series and watch it.

Anyway, this cel is a Diagonal Pan cel, and so 
they cut the corners off, but if they were still
 there the cel would measure 15" X 21" and of
 course the background is even larger.  I packed
 this in my largest suitcase with cardboard 
surrounding it on both sides to get it home safely

I still don't know what to do with it since it is 
so big.  Probably hang it on my wall like a poster

^_^