Mahiro's Panic! At the Hot Spring (Part 2)

'''Mahiro's Panic! At the Hot Spring (Part 2)' (まひろと温泉パニック（後編）, Mahiro To Onsen Paninku (Kōpen)) is Chapter 18 of Onimai: I'm Now Your Sister''. It was originally published on Pixiv on July 28, 2018.

Summary
The drug that turned Mahiro into a girl is starting to wear off, causing Mahiro's "comrade" to regrow. Now she must hide it from Kaede and a suspicious Momiji until a new dosage of the drug turns her female again.

Plot
Mahiro's "comrade" has just grown back while in the hot spring, and she confirms that it has indeed returned. Momiji feels around Mahiro's body until she encounters it by accident. She asks what this "squishy thing" is and squeezes it, causing Mahiro to freak out. She runs away from Momiji calling a time out.

Mahiro runs towards Mihari and calls out to her, eventually gripping her arm when she gets close enough. Mihari is surprised and asks what is wrong, particularly why Mahiro has such a serious look on her face. Mahiro pulls her hand into the water until she is also groping it, and she realizes in horror that the feminization drug is starting to wear off.

Kaede asks Mihari's what's wrong, causing Mihari to panic. She and Mahiro try to laugh it off by claiming the Mahiro is just feeling a bit light headed, even though they are both nervously sweating. Kaede goes closer to Mahiro saying that she does look a bit flushed, which causes the two of them to panic even more. Mihari says that she'll take Mahiro back to her room. She and Mahiro get out of the hot spring and Mihari tells Kaede and Momiji to take their time and that they'll be fine. Mahiro uses a towel to cover her private area so no one will see, though Momiji has gotten suspicious.

After they are fully dressed, Mahiro sits on the ground fidgeting. Mihari says that it seems that the drug has finally started to wear off, and that it is possible that the purifying effects of the hot spring has something to do with it. She tells Mahiro that at this rate she'll be back to normal by morning. Mahiro is shocked and asks what they're going to do about Kaede and Momiji, saying that they'll never look her in the eye again if they find out that she's a guy. She says that she can't deal with this, not while they're stuck on vacation together.

Mahiro remarks that she likes how things are now, but that now it's all over. Mihari hugs Mahiro to comfort her and tells her that it's okay. She mentions how it's not the end and reveals that she brought a new dosage of the feminization drug, much to Mahiro's shock. Mihari mentions how Mahiro said she that she was feeling wierd before they left, so it seemed like it might be time and she brought the drug with her to be safe. Mahiro gets upset, asking Mihari why she didn't tell her.

Mahiro opens the bottle, but Mihari stops her by asking if she really wants to take it, pointing out that she'll be stuck as a girl again. Mahiro doesn't hesitate and drinks the entire bottle. Mahiro tells her not to get the wrong idea, claiming that she's not doing this because she wants to be a girl or anything. Mihari just chuckles and plays along with what Mahiro is saying.

Mahiro opens her yukata to see if her "comrade" has vanished, only to find that it is still there. Mihari tells Mahiro that it will take awhile for the drug's effects to kick in, then tells Mahiro to put her clothes on (as she can see it with the yukata open). Mihari tells Mahiro that it should kick in overnight and that she just needs to be careful for the rest of the day, all while closing up Mahiro's yukata.

Kaede opens the door to the room saying that she and Momiji are back, causing Mahiro to panic. Kaede remarks to Mahiro that she's looking a lot better, and Mahiro just chuckles. Mahiro suggests to Kaede that they have a pillow fight later, and Kaede is driven to so. Mihari is left amused at this.

As all of them prepare to have dinner, Kaede remarks how it all looks so good. Mihari mentions how fancy it is. Mahiro on the other hand notes that this isn't good, as she's been without her "comrade" for so long that now she can't help but notice it there. It gets even worse because of the fact that there is a cute high school girl, fresh out of the bath, sitting right next to her. Mahiro mentally pleads for her "comrade" to calm down. Momiji sees Mahiro's struggle, and this only furthers her own suspicions.

Later, Kaede turns out the lights so everyone can go to sleep. Mihari remarks that today was really fun, and that it felt almost like a class trip. Kaede realizes that Mihari missed her own class trip as she skipped ahead a few grades. Kaede suggests that they travel together again sometime. Mihari agrees, and Mahiro drifts off to sleep remarking what good friends she has and that she also hopes they can too.

During the night, Momiji can't sleep and as she can't stop thinking about what happened, eventually sitting up. She knows that she touched something in the hot spring, but she looked around after and didn't find anything that could've been it. Momiji gets in front of Mahiro, still in disbelief, and apologizes to her saying that she has to check to know for sure is Mahiro is really a guy.

Mahiro is eventually rustled awake by Momiji's checking, and becomes shocked to see Momiji having opened her yukata and now looking at her private area. As their eyes lock, they both become shocked. Momiji says that it is all smooth. Mahiro sits up and feels down below, sighing with relief when she finds that she is once again fully female. As she notes it being a close call, she asks Momiji why she was doing that. Momiji panics, then pretends to go back to sleep. Mahiro knows that she is playing dumb, and wonders what that was all about.

The next morning, Mahiro and Momiji are exhausted from having not slept a wink over what happened. Momiji notes how awkward this is. Kaede asks them what's wrong while Mihari struggles to wake up. Mahiro narrates that her great ordeal continues.

Meanwhile, Mihari feels extremely embarrassed as she cannot believe that she actually touched her own brother's "comrade".

Characters

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