The recent airing of the second series of Hyakka Ryouran Samurai Girls poses the question of why the stylish but lacklustre first season was deemed worthy of a sequel, but also conjures up the spirit of genre stalwarts such as the long running Sekirei and Ikkitousen franchises - each series with a more ridiculous alliterative subtitle than the last - as well as one-offs such as Tenjho Tenge. The specific taxonomy of these series is usually spread between "fantasy", "martial arts" and the all-encompassing "fan service" categories, but works equally well as just "fighting fanservice" (FF).
With a few exceptions, the entire point of these series is to group voluptuous girls together so they can beat seven shades of tar out of one another, usually with disastrous consequences for their clothing and decency. Twice tickling the lizard brain for those who are titillated by such things then: violence and sex. Tweak the variables from breasts to blood though and you have horror (see Blood-C, Elfen Lied, Ga-Rei Zero etc.). Catering to base desires though doesn't leave a lot of room for story or character development with many of the plot lines and episodic stories simplistic even if they were in a children's Saturday morning cartoon and utterly worthless for anything other than hurtling the cast from one arena to the next.