I was asked a curious question by a friend of mine.

She asked me why manga and anime became so popular and influenced Japanese culture and identity.

I replied to her with the following message (this is still not a complete answer): 

I think so too, and manga and anime are great [aspects of?] Japanese culture.
They are similar to comics like Peanuts, X-Men, Spiderman, etc, but I think they have significantly different story lines.

I'm an avid leader in [or an avid reader/consumer of?] anime and manga, and I'll try to provide you with some information soon!
No manga, no life!! (laughs a lot)

Here. [common ways to sign off are Sincerely, Yours truly, or just put your name. In this case, I'd just go with sticking your name at the end.]
Ron