General Background
Kill la Kill was produced by Trigger, which was founded by former Gainax employees Masahiko Otsuka and Hiroyuki Imaishi. Otsuka was the director of Tengen Toppa Gurren Lagann and Panty & Stocking with Garterbelt, which perhaps explains this series' particular animation style. It was a reaction to leaving Gainax's angsty and super-serious Evangelion era at first, then evolved from there and took Gainax to the next level.
Since then, many of the influential figures who came up with the aforementioned titles left Gainax to form Trigger, and that later culminated in this series. In some ways, it has the same western-influenced animation style that its predecessors had, but it then takes it a few steps further as well. The character designs were done by former Gainax animator Sushio and the script was written by Kazuki Nakashima.
As with a lot of things that come out of Japan, Kill la Kill was inspired by the director Imaishi's observations of homonyms and puns. He noticed that the Japanese pronunciations of the words "fashion" and "fascio" (Italian word for fasces, the symbol of fascism) are rather similar, as well as the word for both "school uniform" and "conquer" being seifuku.
The title itself in Japanese plays with the multiple meanings of the word kiru, which can mean "kill," "to cut," and "to wear." It seems that Trigger ran wild with this intricate wordplay, and more of them are found throughout the whole series.
Uniqueness
It certainly looks very different with its striking visuals, great use of color, and distorted sense of scale, but what really makes Kill la Kill stand out from the crowd is its treatment of its central theme. The super power genre is mostly split into two groups. Either it's mostly male characters with lots of fighting or "mahou shoujo" (magical girls) shooting magic at bad guys.
But with Kill la Kill, it's a mix of both - female characters in school girl uniforms transforming and swinging swords at each other. The high school girls and the long transformation sequences suggest "mahou shoujo" trappings, but the plot and combat suggest it leaning towards the "shounen" (boy) genre. It sets out to not marginalize its audience, but pull them from all directions and hit them at weird angles.
Kill la Kill is also rather divisive with the prodigious use of skin throughout the series. While there are plenty of anime that use suggestive and/or overt nudity for fan service, Kill la Kill seems less about that as the nudity becomes more and more prevalent. They make use of the dichotomy between clothes and nudity with the tyranny of Life Fibers and finally being free from them. At the conclusion of the last battle, everyone is naked and it's actually alright.
Perhaps the highlight of every episode is the transformation sequence with the chorus of the song "Before My Body is Dry" that serves to hype up the fight scene to come. It takes elements from "mahou shoujo" and "tokusatsu" (films with a lots of special effects), combining them into a sequence that looks both sexy and badass at the same time.
Similar Titles
Other anime that immediately come to mind as similar to Kill la Kill are indeed its Gainax-made predecessors such as Tengen Toppa Gurren Lagann, Panty & Stocking with Garterbelt, and FLCL. However, there are then some interesting titles outside of Gainax and Trigger that are worth looking at.
Shoujo Kakumei Utena
Also known as Revolutionary Girl Utena, this 39-episode series is about a girl named Utena Tenjou, who wishes to become a prince. Upon attending Ohtori Academy, she becomes close with Anthy Himemiya, who had been in an abusive relationship with another student. Vowing to protect her, Utena fights in sword duels with the Student Council for the right to possess the "Rose Bride," who happens to be Anthy herself. If you're into a high school girl fighting other students with a sword like Ryuuko Matoi does in Kill la Kill, then this series may hit that spot.
Needless
In the year 2130, 50 years after World War III, Japan had been left with a crater where Tokyo once stood, known as the Black Spot. It has been quarantined and is now populated by outcasts, some of whom had gained powers called "fragments" due to contamination. They're known as the Needless. This series gets quite close to Kill la Kill in terms of absurdity and hyperactive action, great for those who like their high-energy anime.
Dead Leaves
Pandy and Retro find themselves stranded and naked on Earth. After much mischief, they get arrested and sent to the lunar penitentiary known as Dead Leaves. They soon learn that the place is more than just a moon prison. [Dead Leaves] seems to be as crazy as Kill la Kill most likely due to sharing the same director, Hiroyuki Imaishi. Frenetic and over-the-top action with boisterous characters seem to be the signatures of his style.
Hells
Amagane Rinne dies in an accident while hurrying to school. She then wakes up in a different school located in Hell, filled with demons. As she struggles in the new environment, the thought of being dead, and wanting to go back to the world of the living, she starts to bond with her demon schoolmates. Hells is similar to Kill la Kill in terms of art style and animation. If it were the first time for you to see both and you look at them side-by-side, you may find the character designs and execution to be near identical.
Rolling☆Girls
Ten years after the Great Tokyo War, the prefectures of Japan have split up into independent nations, with each governed by a a prophet called "Mosa" and an army called "Mob." Nozoki, Yukina, Ai, and Chiaya are four Mob girls from the Saitama clan who are ordered by their Mosa to travel around Japan on their motorcycles to oversee battles between nations and clans. From the female main characters, the costumes and uniforms worn in combat, to the over-the-top action scenes, Rolling☆Girls is recommended for those who want something with a roughly similar tone to Kill la Kill.
Abashiri Ikka
Abashiri Ikka is a 4-episode OVA where the daughter of a gang boss gets sent to a private boarding school so she can learn to be a proper lady. However, the school turns out to be a battleground in itself with crazy teachers and unfriendly classmates. Abashiri Ikka is similar to Kill la Kill in terms of its school girl protagonist with fighting abilities and a mean streak, and the school setting full of other students looking to fight her. Despite that, this short series predates Kill la Kill by 23 years.
Who Should Watch It?
Kill la Kill is for those who enjoy lots of action blended with a good bit of comedy in between. If you liked Tengen Toppa Gurren Lagann for its over-the-top action and its characters' excessive show of boisterous defiance against a common enemy, then you'll like Kill la Kill for the same reasons.
But if you just can't stand any sort of sexually suggestive imagery on your anime, no matter what the context, then you may have to skip this series. While the show of skin here matters less as it becomes more of the norm towards the latter parts of the series, there are bound to be viewers who just can never look that that and be comfortable watching it, which isn't really wrong.
Other than that, Kill la Kill is recommended viewing for anyone who just likes a fun action-packed anime. It's paced very well, writing is fairly consistent, characters are memorable, and is a wild ride from start to finish.
Perhaps you may need to take it easy if you're planning to marathon this series as it may not be that conducive for binge-watching, but it's certainly something you have to queue up if you haven't yet.
