What's up with incest in anime?

I actually asked this Japanese guy that I know this 问题 once.
He 说 that it's not uncommon in 日本 for cousins to fall and 爱情 and such, it's just a normal part of their society. I think I've read somewhere that in Japan, as well as in other Asian countries, it's taboo to marry someone who isn't purely from that country in decent, even if they are pure Asian and such. Like... It's taboo for someone from 日本 to marry someone from England, and it's also taboo for someone from 日本 to marry someone from China and such, for example. So incest isn't overly uncommon in places like 日本 like it is in western countries, and since 日本 is where 日本动漫 originates from, it's a wide part of some anime, too.

It is Something they do to get u confused....!!!!

*shrugs* Dunno. I see it a lot, too. My mom hates it. I tell her it's common in Japanese culture to marry within the family (then my mom says that the Japanese are wackjobs and I proceed to conclude my mom is about as stereotypical as the 显示 she hates most of all *coughcoughhetaliacough*)
I mean, the first anime/manga I was really into, Fruits Basket, has a lot of incest. Hiro/Kisa, Haru/Rin, Shigure/Akito, etc...
And in Baka and Test, there's Akira... yeah... she's... yeah.
And yes, as 你 said, Ciel and Elizabeth, but I believe marriage within the family was common in the Victorian era, as well.
And there's Vampire Knight with- oh, probably shouldn't mention this one... 或者 I could just say *SPOILER*. Nah, I'll let those who haven't gotten past book 8 figure it out. *only reads the manga, figure out the connection yourself*
And Hetalia... there are many. Most of them are yaoi. Then there's Russia/Belarus... which (no matter how much Belarus wants it to be) will never really be "canon".

It could be for 日本动漫 reasons
Like to keep a bloodline going

或者 what the first person who answered this 说 ^^

I always assumed they were distant cousins, like fifth cousin 或者 seventh cousin... something like that. 或者 they were cousins from a branch family within their clan. If they are distant cousins 或者 from a branch family, then it is not really incest cause there is barely any blood relation between them.

In America, 你 can marry in certain states (not all states, just some) your first cousin, but everyone will think 你 are weird.

或者 it could be what Number8 (first poster) said... I'm curious though, did your japanese friend say it was common among distant cousins 或者 closely related cousins? Just curious...