Mahiro's Panic! At the Hot Spring (Part 1)

'''Mahiro's Panic! At the Hot Spring (Part 1)' (まひろと温泉パニック（前編）, Mahiro To Onsen Paninku (Zenpen)) is Chapter 17 of Onimai: I'm Now Your Sister''. It was originally published on Pixiv on June 30, 2018.

Summary
Mahiro, Mihari, Kaede, and Momiji head on an overnight trip to a hot spring.

Plot
Mihari comes into Mahiro's room asking if she's ready, and finds Mahiro slumped on the ground all gloomy. Mahiro remarks that the day is finally here, that day of the overnight hot springs trip that she, Mihari, Kaede, and Momiji planned weeks ago. Mihari is confused and reminds Mahiro that she was really excited for this. Mahiro remarks that she was, but as time passed she started feeling really weird. Mahiro starts to think that she's having a "leaving-the-house" allergy. Mihari starts to wonder what is really going on.

The group finally arrives at the hot spring, but Mahiro is not eager to go in, saying that she can't take it any more. Kaede tries to encourage Mahiro saying that it is just a little bit further. Momiji just thinks that Mahiro is tired from traveling. Kaede suggest that they check in so they can relax, which perks Mahiro up and leads to them saying "let's do it". Mihari notes to herself that Mahiro is good at this, but is still not completely on board about going to a hot spring. She knows that they all settled on a hot spring, but wonders if it's actually a good idea for Mahiro to bathe with them. She knows that she feels bad for Kaede and Momiji, but knows that it would be weird to insist on bathing separately. Kaede says that she's got the room key, and Mihari suddenly grabs Kaede's hand and blurts out that she'll protect her. Kaede is confused and asks Mihari if she wants the room key.

In the room, Mahiro is amazed at how traditional it is with tatami mats. Kaede is also impressed by how big it is. Mahiro lays on the ground and relaxes, saying that she is so refreshed. Kaede says that the truly refreshing part is yet to come and asks Mahiro if she forgot about the hot spring. Mahiro says that she knows, leading Mihari to think how shameless Mahiro is. Kaede suggests that they all rest up for a bit and then head straight for the hot spring.

Mihari remarks that they take the towels from their room. Kaede starts to wonder what they use for their after-soak clothes, when Momiji comes in a new outfit. Mahiro doesn't recognize Momiji, again, much to Momiji's annoyance. Kaede, after seeing this, remembers that they wear yukata for that purpose. Mahiro realizes that it is Momiji, and Momiji remarks how relaxing the yukata is. Kaede remarks that they should all get changed an go then.

Kaede starts to undress saying that the yukata make this place feel so rustic. Mihari panics at the act of Kaede undressing. When Kaede starts to turn towards her to ask what's wrong, Mihari pulls Mahiro's face towards her chest and laughs it off. Mihari tells Mahiro not to stare when they're in the bath. Mahiro doesn't know what she means, then realizes that she's talking about not starting at Kaede or Momiji who will be completely undressed in front of her.

Kaede tells Momiji that she looks great in her yukata, but Momiji feels embarrassed and tells Kaede not to tease her.

Mahiro realizes that this situation is just like a public bath, and that she was so worried about the trip there that she didn't even think about the hot spring itself. She thinks to herself that Kaede is going to be naked in front of her, but quickly tries to shut out the thought as they're just friends. Mahiro realizes that she needs to keep her guard up, as even her moral code doesn't allow for thoughts like that.

Mid-thought, Kaede strips off her clothes, exposing her entire front and Mahiro gets amazed by it. Kaede leans forward and tells Mahiro that she needs to take her clothes off as well, but Mahiro can just stare as Kaede's naked form gets even closer to her. Kaede starts doing it for Mahiro saying that there is no need to be shy. Mahiro tries to tell Kaede to stop while Mihari looks at Mahiro disapprovingly for staring when she said not to. Mahiro thinks to herself how this is torture.

Later in the hot spring, Mihari and Kaede relax on one side with Kaede noting how relaxing this is. Mihari reads a sign that says that hot springs are good for detoxing, and Kaede remarks that this is certainly a good detox.

Kaede invited Mahiro, who is sitting further away, to come and sit with them. Mahiro tells Kaede not to mind her, and Kaede chalks up Mahiro's shyness to puberty. Mahiro remarks how on edge she is, and it doesn't help when Mihari lets out a piercing glare towards her. Mahiro decides that she can't help it and goes to a different part of the hot spring, deciding that it will be dangerous if Kaede comes near her.

Mahiro finds a secluded spot and relaxes, noting that bathing alone is definitely better. Mahiro remarks that she never heard of a hot spring making you more stressed. Mahiro feels a twinge and notes that that weird feeling is back again, and wonders if she's just stressed out.

Momiji finds Mahiro and suggests that they stick together, with Mahiro becoming surprised. Momiji notices that something's wrong and asks about it. Mahiro remarks that she guesses that she is safe with Momiji, and Momiji asks her what she means. Mahiro remarks that she doesn't have to alert her gaze from Momiji, thinking to herself that it is just like looking in a mirror.

Momiji, who didn't hear the last part, attacks Mahiro from behind and asks why not, asking if it is because she's flat chested. Mahiro is surprised and insists that that's not what she meant. Momiji tells Mahiro that she'd better say that she's sorry and begins tickling her from behind. Mahiro laughs while saying that this is bad and really getting out of hand.

Mahiro then feels a throbbing sensation and becomes alarmed. She notes that it is a firmiliar feeling, one that she thought that she would never feel again. The feminization drug has started to wear off, and her "comrade" has grown back, and while she's naked in the hot spring with Momiji nonetheless.

It is also revealed that Mahiro saw before that Momiji didn't wear a bra under her yukata, and wished that she could do that. Although it is due to Momiji not filling out yet, she embarrassingly insists that you don't need to wear one with a yukata.

Characters

 * Mahiro Oyama
 * Mihari Oyama
 * Kaede Hozuki
 * Momiji Hozuki

Trivia

 * This chapter is a follow up to the events described in "Mahiro Attends a Party" when Mihari suggested that the four girls take a trip, with Kaede recommended going to a local hot spring.
 * The chapter references how Mahiro previously failed to recognize Momiji in a different outfit in "Mahiro's Wholesome Playdate" after she does so again here.
 * This chapter marks the first instance of the feminization drug starting to wear off.