Mahiro and the Middle Schoolers

Mahiro and the Middle Schoolers (まひろと中学生, Mahiro To Jūgakusei) is Chapter 20 of Onimai: I'm Now Your Sister. It was originally published on Pixiv on September 29, 2018.

Summary
Tired of Mahiro laying around the house all day, Mihari arranges a get together with Momiji and some of her friends.

Plot
Mahiro is lying in her bed playing a handheld game. Mihari tells Mahiro that it is past noon on a weekday and yet she is still loafing around. Mihari asks Mahiro if she'll go and play outside at least, leading Mahiro to ask if Mihari thinks that she is their mom. Mahiro points out that she could get busted by the truant officer again, and Mihari realizes that Mahiro is right. Mahiro lies back down, remarking sarcastically that it is tough, being stuck inside all day like this. An exacerbated Mihari thinks to herself that she can't let this continue and that she has to do something.

Later, Mahiro takes a nap on the living room couch. Mihari notes to herself that Mahiro has gotten better over these last few months, but also notes that she'll still be a deadbeat if they don't shake things up. She thinks that it is time for the big guns, but notes that it'll take some effort.

The doorbell rings and Mihari answers it. Mihari is seen saying to the person at the door that she realizes that they came straight from middle school and that Mahiro is taking a nap. Mahiro gets up, believing it to be Momiji and walks to the door to say hi. It turns out to be Momiji, who says hi, as well as two other girls that Mahiro hasn't seen before.

Mahiro is confused and hides behind Mihari asking who those girls are. Momiji apologizes and tells Mahiro that they are her friends from school. She further explains that they were on their way to a café for parfaits and was wondering if Mahiro wanted to join them. Mahiro is scared at the prospect, but Mihari sees the golden opportunity that she was looking for.

Mahiro tries to claim that she would love to, but just remembered that she has something to do. Mihari then says to Mahiro that the offer is nice, and claims that Mahiro was just saying that she had no plans for the afternoon. Above Mahiro's protests, Mihari gives Mahiro money for the café. Momiji then begins to push Mahiro to the café, above Mahiro's confusion. Mahiro realizes that Mihari set this whole thing up on purpose while Mihari waves her off. Mihari then grins and notes that it is now time for the hard part.

At the cafe, Momiji introduces the two. The girl with the long hair on the right is Miyo. The other girl with the pigtails introduces herself as Asahi. Mahiro introduces herself as well, but cringes inside wondering how she got into this mess. She then realizes that she needs to calm down, and can't let some middle schoolers get to her like this. She realizes that she just needs to stay cool and collected like the the adult that she is. While doing this, she unconsciously grips Momiji's left arm. Momiji pushes Mahiro off telling her not to get so close, and Mahiro apologizes. Miyo gets aroused by what just happened and comments that the two must be very close, much to Mahiro and Momiji's confusion.

Asahi, giving Mahiro a nickname "Mahiron", remarks to Mahiro that Momiji has told them all about her. Mahiro is shocked that Momiji has done so, and also that Asahi is giving her a nickname after only having just met her. Asahi tells Mahiro that Momiji said to them that she's funny and cute. Mahiro is surprised by those comments. Asahi adds that Momiji also said that Mahiro was a lazy good-for-nothing coward who's afraid of crowds. Momiji is shocked that Asahi would repeat that back, and claims that she didn't mean it in a bad way. Mahiro just laughs at that remark, much to Momiji's surprise, admitting that it's fine and all true anyway. She remarks that it's easier to own up than to live up to someone's expectations.

Mahiro slumps down on the table saying that she's not anxious at all anymore. Asahi is glad, while Momiji claims that you can't just brush something like that under the rug. Momiji apologizes for Asahi being a jerk. Mahiro is surprised that Momiji is badmouthing her, and Momiji laughs at that saying that they've been friends since elementary school. Asahi confirms this statement. Miyo whispers into Mahiro's ear telling her not to worry as they're not really all "that close", which leads to Mahiro wondering what Miyo is talking about.

The waitress brings out the parfaits and apologizes for the wait. Mahiro is amazed by them, and remarks that this might be her first parfait ever. Momiji remarks that they have tons of different flavors here. Asahi offers her spoon to Mahiro, much to her surprise, saying that she can have a bite of her chocolate banana parfait as an apology. While Mahiro is confused, Momiji eats the bite herself, which leaves Asahi surprised. Momiji then forces her spoon into Mahiro's mouth saying that she can have some of hers. Mahiro is confused by what is happening while Miyo gets aroused again. Momiji asks Miyo if she wants some too, but Miyo says that she is already full.

The girls eventually finish their parfaits and all comment on how good they were. Outside, Momiji says that they are all going to split up from here, while Asahi suggest that they do this again sometime. Mahiro agrees to it so long as she's in the mood. Mahiro thinks to herself that she wasn't sure about this at first, but that it turned out to be fun. Miyo then calls out to Mahiro. She grips Mahiro's hands, while aroused again, and tells her that she supports her 100%. Mahiro wonders if Miyo is okay.

Back at home, Mihari grins and asks Mahiro how her "date" was. Mahiro asks her not to call it that, but remarks that the parfaits were good. Mihari accepts the answer and congratulates Mahiro for surviving. She remarks that she is about to start dinner, and suggests that Mahiro hop into the tub. Mahiro agrees to that.

After cleaning up, Mahiro takes a look at what clothes have been laid out for her today. She becomes shocked to see that it is Mihari's old middle school uniform. Mahiro notes that somehow this looks very firmiliar. Mihari beams at how Mahiro looks, remarking that she was concerned about it being a hand-me-down but that it fits perfectly. She tells Mahiro not to forget the blazer, and Mahiro tells her that she is not her dress-up-doll. Mihari tells Mahiro not to be be like that. She add that she was worried about all this, but that the drug seems to have stablized. She also adds that Mahiro seems to have made some new friends as well. She starts to add on something else, that makes Mahiro concerned, and tells Mahiro that she should go to school.

It is also seen that Mihari put on her old uniform herself earlier and, even just barely, was able to fit into it. She wonders if it still looks okay, even though she's clearly outgrown it.

Characters

 * Mahiro Oyama
 * Mihari Oyama
 * Momiji Hozuki
 * Asahi Ōka
 * Miyo Murosaki
 * Tsurara Kamito

Trivia
第20话
 * First appearances of Miyo Murosaki, Asahi Ōka, and Tsurara Kamito, though the latter is not named here.