In the November 2014 issue of Kodansha’s Monthly Shonen Magazine, Shingeki no Kyojin (Attack on Titan) author, Isayama Hajime did a little Q&A with fans. One answer was quite surprising.
When asked “Out of the group of female characters in the 104th Trainee Squad, who did Mikasa get along with the most?” Isayama answered “Armin” 
which is not what anyone expected because everyone thought that Armin Arlert was male. This as lead to a number of fan sites to explode and wiki sites to be changed. I bet this makes Josh Gelle feel a little strange as he does the voice for Armin in the English Dub. The Japanese voice for Armin is done by Marina Inoue but it’s not uncommon for women to voice male characters in Japan especially if they are young male characters. Even Marina has voiced for young male characters, most notably being Shu the main character in Blue Dragon video game.
Anime characters not being the gender they appear is a quite common trope. Some examples would be:
 |
Haruhi Fujioka (female) |
Ouran High School Host Club |
 |
Seishirou Tsugumi (female) |
Nisekoi |
 |
Ruka Urushibara (began and ended series as male) |
Steins; Gate |
 |
Haku (male) |
Naruto |
 |
Grell Sutcliff (male) |
Black Butler |
Those are just some examples of gender confusion, but those cases the confusion was cleared up early on into that characters introduction.  But with Armin, no one knew except Isayama Hajime seemed to know. If you do a google image search of Armin even with save search on you get a lot of suggestive images of Armin and Annie together or Eren and Armin or Armin and Levi or Armin and Jean. It gets a little uncomfortable with all the BL, boy love (yes I know the term).
Some of the other quetions were:
Q: Â Who eats more, Gal Sone or Sasha?
A: Sasha eats more.  She won’t lose when it comes to eating.
Q: Mike smells all kinds of stuff, how does a titan smell?
A: They smell like a spa-town.
Q: Does Levi help out preparing food for his squad?
A: He does the cleaning.
It was the whole Armin is a girl thing that really stuck out to fans.
