"I'm home."
Yumiko stepped through the front door, outwardly calm. Inwardly—a little tense.
Her sister had seen her with Mio just yesterday. If she spotted Mio now, she'd definitely say something. Yumiko didn't particularly care what her sister thought, but if Mio got the wrong idea from whatever came out of her sister's mouth...
She scanned the entryway. No sign of her sister. Mom didn't seem to be home either.
Good. She exhaled quietly and started laying out guest slippers—
"Oh my, if it isn't my adorable little sister~ Back so early today~"
Her sister's voice floated in from somewhere down the hall, just as she rounded the corner—and stopped the moment she saw the silver-haired girl standing in the entryway behind Yumiko.
She blinked. Looked again.
That very distinctive white hair—wasn't this the cute girl from yesterday? The one who'd been all over Yumiko?
And now Yumiko had brought her home the very next day.
...Maybe she'd been underestimating her little sister.
Though to be fair, she herself had never brought a girlfriend home this brazenly.
...She also didn't currently have a girlfriend. So. Different situation.
Mio, meanwhile, had already swapped her shoes out and was bowing politely. "Hello. I'm Shirai Mio—Yumiko's friend."
"I'm Yumiko's older sister! You can just call me Big Sis, same as Yumiko does~"
"Hold on." Yumiko's eyes went sharp. "When have I ever called you that?"
Her sister caught the warning perfectly. Normally she'd absolutely take any opportunity to torment her little sister—but there was a guest here. A guest whose relationship with Yumiko seemed to be... something. She'd be on her best behavior.
For now.
"Ah—actually, I just remembered, I still have homework." She made for her room. "I'll head back. Oh, and Yumiko—Mom won't be home for about another hour. My music will be on, so even if you and your friend want to..." She let the sentence hang, loaded.
Yumiko reached out and physically pushed her back through her bedroom door.
Clunk.
From behind the closed door came something that sounded like: "...Got a girlfriend and completely forgot about her big sis..."
Yumiko let out a slow breath and turned back to Mio. "Sorry. She's a little... much."
"I don't know—it's kind of fascinating, actually," Mio said thoughtfully. "You two are sisters. How did your personalities end up so different?"
"I ask myself that every single day."
Clearly done with the topic of her sister, Yumiko changed tracks. "Anyway—you should take a bath first. You can borrow some of my clothes, is that okay?"
"Of course~" Mio's voice dropped to something deliberately warm. "But what about you, Yumiko? How about we go together~?"
...Okay. There had been the tiniest flicker of something in Yumiko's chest for exactly half a second. She stamped it out immediately.
"No. I'll use my parents' bathroom."
"Aww~"
"Stop 'aww'ing at me!" Yumiko physically hauled Mio to the bathroom door, shoved a towel into her hands, and clicked the door shut before anything else could happen.
A minute later, she came back with a change of clothes and left them just outside.
She stood there for a moment. From behind the door, she could hear water running and Mio humming something to herself.
"I put clothes outside the door—just reach out and grab them when you're ready. My room's upstairs, there's a nameplate. Come find me when you're done."
"Got it~"
Satisfied, Yumiko turned to head to her own bath—
And nearly walked face-first into her sister, who was leaning halfway out of her room with an absolutely incriminating expression.
"...Yumiko," she said, grinning. "How come you're not in there with her? I could've sworn I just heard—actually, y'know what, never mind."
She pulled her door shut.
Yumiko stood in the hallway alone.
I need someone to come take this sister off my hands. Like what had happened to their brother—the moment he'd started dating, he'd turned into a perfectly reasonable human being. Yumiko needed that to happen to her sister. Urgently.
When she came downstairs after her own bath, she found Mio already settled in the living room—in conversation with her sister—and both of them looking far too comfortable.
Her heart lurched. She crossed the room fast.
"What are you two talking about?"
"Oh, nothing~" Her sister beamed. "Just some very interesting things about a certain Yumiko~"
"We were talking about cooking," Mio said, with the most impeccable timing and completely neutral expression imaginable.
Oh. The tightness in Yumiko's chest eased a little.
...Though she wasn't sure why she'd been so alarmed in the first place.
Her sister, reading the room, made a show of suddenly remembering her unfinished homework and retreated. Yumiko sat down beside Mio.
"Come on. My room."
"Sure~ Hey—should I give you a minute to tidy up first? In case there's anything in there you wouldn't want me to see?"
"There isn't. Let's go."
"Then let's go~"
Yumiko shot her a look, then turned and headed upstairs.
She could hear Mio following behind her, clearly thoroughly unbothered about everything.
...