Hello!! I would like to explain the word " otaku".
Otaku is those people who are interested in comics, games or animation. And Akihabara is a Mecca for them. They visit Akihabara frequently and are putting all their energy into such specific tastes.
Next, I explain the word " moe".
Moe is pink fuzzy warm feeling when see cute girl wearing a costume such as character of comics or games and maid.