Kamenashi Kazuya is the least they have in common.
Two good shows. That don't just happen in life, they teach a bit about life. A ghost-looking being temporarily transformed into a female almost-socialite. Can get you emotional. About friendship, less, or more. Includes some comedy and some heaviness. The obvious thing - it really is two shows with the 'makeover' premise. NwP has a Mr Popular character and in YNSH there's a four-piece set of downright princes. Kamenashi's character is a partial jerk in both. Both the girls rock as they are. Youth. I just want you to watch both shows.
YNSH is a bit more straightforward with the romance (plus there is "supporting love"; but generally, it doesn't feel *that* much like there's more)
while Sunako is kind of annoying, Nobuko is a more pure spirit
what can I say, YNHS has all those skulls and chocolate, NwP has an absolutely wonderful ..alien? called Akira ..
NwP is a bit more serious