America and the West have created many innovative terms to describe people who are obsessed with Anime and Japanese pop culture and fashion. There’s the otakus and the weeaboos and weebs.
In America, at least from New York where I am from, the term “weeaboo” and “otaku” is not necessarily derogatory, and some die-hard Japanese culture fans will proudly pronounce themselves as so. There is no real stigma involved and it’s generally looked at by outsiders as just another extreme niche.
But in Japan the term is not a compliment. One would definitely not be happy to be called an otaku, especially if they do not view themselves as one. Otaku here are the type of people who spend a significant portion of their resources, especially their income, on Anime goods and cosplay. They will collect manga, action figures, CDs, badges, clothes and accessories, and pretty much anything related to their obsessions.
Because it is so obsessive, it is seen as irrational behavior by most people outside of this group, and they will often try not to associate themselves with otaku. Otaku often seclude themselves in their home, and spend much of their free time watching anime, reading manga, and maybe chatting online with people who share similar interests.
It is not necessarily bad to love anime and manga. Most people grew up with one special series that they fell in love with and respect to this day. For me it’s Naruto and Fullmetal Alchemist. But there is a line, and it’s pretty wide, that divided the normal amount of admiration from the obsessive, irrational nature towards these things.
For me the Anime and pop culture is sort of an art to be admired because creators do spend a lot of time and energy to do what they do, but one should not let their life be controlled by the otaku world.