Tsukihi Araragi

Tsukihi Araragi is a character from the Bakemonogatari franchise. Living in the Araragi residence, she has her Baths in the house's Slipper Bathtub and has started taking all of her baths with her sister Karen Araragi right before the time of Nekomonogatari: Shiro arc. As revealed in the Tsukimonogatari arc, she has no problem being seen naked and bathing with her older brother Koyomi Araragi and that she sweats alot and bathes whenever she can being compared to Shizuka Minamoto from Doraemon by Koyomi.

Episode 2
At the beginning of the episode, Koyomi Araragi gives an introduction of his younger sisters and when he talks about Tsukihi, a visual of her naked on top of water is shown.

Episode 3
Tsukihi is seen coming out in panties and a Towel on her head after an Off Screen Bath.

Episode 3
Tsukihi and Karen Araragi have a Furo session together where Tsukihi is seen sitting on a Bath Stool and getting her very long hair Shampooed by Karen while wearing a Shampoo Hat and having the Shower run on her. The both of them then share a Bath in a Slipper Bathtub with Tsubasa Hanekawa.