Both male and female fans can call themselves "otaku," especially in the West. More often than not, however, "otaku" are male fans in Japan. The fact that American fans call themselves "otaku" is actually counterintuitive, as the term is an insult in Japan.
"Otaku" literally means "house." In Japan, the label can apply to an obsessive fan of any hobby, but most often refers to anime fans. The idea is that these fans are so obsessed, they rarely leave their homes. In America, fans often call themselves "otaku" when they're proud of their extreme level of devotion to anime. However, there are a few differences between the Japanese "otaku" and the American "otaku." Japanese "otaku" are more obsessed with expensive merchandise and watching as many series as possible; in general, American "otaku" prefer less expensive merchandise and devote themselves to a smaller number of shows.
"Fujoshi" are female anime fans only. Although largely a term that applies to Japanese female fans, the term appears among American fans as well. "Fujoshi" literally means "cultured lady," but the Japanese characters spelling the word have been swapped with characters that mean "rotten woman." The term is a tongue-in-cheek reference to the hobbies a "fujoshi" enjoys. The term "fujoshi" originally referred to female fans who were obsessed with anime featuring gay love between male characters as well as fan-made stories pairing two male characters together in a romantic story. However, the term has evolved to refer to hardcore female fans of any type of anime.
At a 2006 American anime convention, one fan claimed to have spent over 80 hours and $50 handcrafting a costume of an anime character for her to wear to the convention. Fans who demonstrate this kind of devotion call themselves "cosplayers." "Cosplay" is a Japanese term derived from two English words: "costume" and "play." Japanese cosplayers dress up as characters from any form of fiction and not just anime. In the West, "cosplay" nearly always refers to dressing as characters from anime and manga (Japanese comic books). In both Japan and America, female anime fans comprise the majority of cosplayers, but a large segment of the cosplayer population is male as well.
Both male and females fans can be "doujinshika," also known as "doujinshi creators." "Doujinshi" is a Japanese word referring to original as well as fanfiction underground manga (Japanese comic) publications. Since fans can more easily create their own manga than their own anime, anime fans with a creative side and a talent for art create their own original manga, known as "doujinshi."
"Doujinshika," as well as fans of "doujinshi," make up a large segment of anime fans in Japan. Conventions selling "doujinshi" alone, known as "comic markets," attract hundreds of "doujinshika" each year. "Doujinshika" make up less of the American anime fan market. However, they often appear at anime conventions in the "Artist Alley" section.