Fan service is a hot-button topic when it comes to any anime, but perhaps no anime has dragged fan service to the front and center like Kill la Kill. While the risqué battle outfits are some of the most revealing of any televised anime to date, it can be argued that the characters chose their clothing as opposed to ending up half-naked due to being battered in a fight. Looking closer, the situation with Kill la Kill's fan service isn't as easy as 'there was' or 'there wasn't,' and instead reveals a show that subverts its actions in a mockery of its own existence.
Kill la Kill was the first anime series by Studio Trigger, which was formed by employees from Gainax after the success of Gurren Lagann. Gurren Lagann didn't hold back with a revealing outfit for Yoko Littner that held no real purpose besides fan service, so it's fair to assume that the same artists who worked on Gurren Lagann felt comfortable designing their female characters with some level of sex appeal. However, Kill la Kill does something very different from Gurren Lagann that makes the Kamui outfits leagues away from an ill-fitting bikini top, flipping fan service on its head to make nudity mean nothing by the end of the show.
Ryuko Matoi's everyday outfit, the sentient sailor suit Senketsu, is similar to the sailor suit worn by many magical girls. When transformed, Senketsu is far more revealing, and toward the beginning of the show, Ryuko earns a lot of comments where she defends herself with the fact she didn't want to wear Senketsu at all. Satsuki is treated with a bit more respect when she dons Junketsu as her battle armor, but both Kamui outfits are undeniably partially there for the sex appeal.
Moreover, the audience is told that this is okay. From characters 'enjoying the view' to developing nosebleeds when Ryuko's outfit catches, the show invites viewers to see the uniforms as sexy. The girls also don the Kamui outfits of their own volition in a way that gives them far more power over their appearance than when women in other shows have their choice of clothing torn off during a fight.
However, things begin to change just before the midpoint of the show, when Ragyo Kiryuin takes over as the antagonist. Nudity stops being tantalizing and is instead a cause for shame. When characters were shown nude before, they were generally cowardly, abrasive or overly obnoxious. It's very different when the three-star students of Honnoji Academy, whom the audience has been getting to know, all trudge away naked after being defeated by Ryuko. They have no honor in being seen this way, making the usual nudity more uncomfortable. When Ragyo takes over and Satsuki's plan is revealed, the show completely flips the fan service around.
With Ragyo in charge, nudity is used as a tool for manipulation and torture, particularly when Satsuki is strung up naked as a means of punishment. The audience is meant to be disgusted and disturbed, and even though characters might be showing more skin than ever, there's nothing sexy about it. Kill la Kill becomes a subversion of its own fan service, posing the question of why it was 'sexy' for Ryuko to be stared at in her Kamui while Satsuki is uncomfortable to watch.
The second half of the show raises a lot of questions about the first, willing to take itself apart in order for new points to be made. When characters begin running around with absolutely nothing on, but with no details shown beyond the basic shapes of their bodies, the irony reaches a climax. Satsuki, who once battled it out in Kamui that left little to the imagination, runs naked to catch Ryuko as she falls from the sky, and then the cast collapses into a pile of nudity, completely sexless and without any fan service whatsoever.
Kill la Kill's shifting views on nudity and fan service itself make it very hard to pin down. There is certainly fan service in the show, but the end message seems to advocate for less fan service, and Studio Trigger has never done anything near the level of Kill la Kill again, Little Witch Academia and Brand New Animal being great examples. Seeing Trigger's general move away from fan service certainly lends credence to the idea that, no matter how much publicity Kill la Kill garnered, it isn't a story the studio is looking to tell over and over again -- so for the most revealing battle outfits, it's likely best to look somewhere else.
