Learning Japanese from popular culture such as anime and manga is nothing new. Mangajin, a magazine from the early 90’s used manga to teach lessons. In fact, it’s exactly these things that inspire westerners to want to learn to read and speak Japanese. The Japanese have recognized this and have created a website to help learners of their language. But it’s not exactly what you’d expect.
The website, anime-manga.jp doesn’t show you manga panels with translations. No, the purpose of the site is to help teach learners about colloquial expressions that often show up in anime and manga, but not in textbooks. Languages are fluid, they are always changing. Anime and manga, which are all about popular culture reflect these changes, which often stump new readers who don’t live in the culture and see and hear these changes. On the site, you can see and hear expressions from typical characters from anime and manga such as school age boys and girls, butlers, and samurai. You can even hear an Osaka dialect from an old man!
I’ve heard people try to discourage others from using anime and manga as a resource for learning Japanese precisely because of the colloquialisms. But in order to sound like a real native speaker, you should know them, and I think it’s great that the Japanese recognize this and are reaching out to foreign learners to help them. Of course, I’m sure all the raw manga and anime these learners will buy to help their studies won’t hurt either.