The girl with the horns in Tenshi ni Narumon is
"Muse."  She's a crybaby and overly humble/polite
at times.  She has lots of silly and sometimes
annoying plans.  Though she seems shy, she can
actually be quite pusy.  She has the ability to
change shape (and abilities apparently).  I went
through ups and downs liking her, but I liked her
by the end.  Nice cels!

Keys
Who's been identifying TnN chars in lots of cels
for people recently