One unique aspect of the Japanese language is the great difference between male and female speech, including gender-specific pronouns, e.g. the word for "I" is ore (oh-reh) for boys trying to appear more manly than they are, and atashi for feminine girls. It's a (minor) issue for foreigners studying the language, since it can be all too easy for a male to pick up the speech patterns of a girlfriend or female teacher, which can be embarrassing. The gap between female and male speech is explored in the new anime Kokoro Connect, about a school Cultural Research Club where the members inexplicably start to switch bodies, with male club members suddenly finding themselves in the bodies of female members and vice-versa. This leads to interesting scenes in which a female character speaks with the voice of the male character whose body she has switched with, using female inflection and pronouns despite the voice itself being male, as well as female characters using masculine speech when boys have swapped bodies with them. It's quite an interesting exploration of what makes us who we are...it's also more than a little sexy.
The new body-switching anime Kokoro Connect.