You're seated on the couch, reading your favorite manga when your sister Ruby leans over the backrest to hug you from behind with a heavy sigh.

"Ahhh, I'm beat," she breathes the words out, embracing your shoulders tightly. Her breasts gently press against the back of your head, a tender blush on her cheeks.

"Onii-chan, give me some of your juice~" She quips before getting a mischievous expression, her eyes trained on your juice box.

"No. Get your own," you reply coldly, not even glancing away from your book. As you speak, she leans down and steals a sip from your juice box.

"Too late," she utters coyly, rubbing your shoulders. "You snooze, you lose juice~" she finishes with a purring lilt.

She nuzzles against the side of your head, wrapping her arms loosely around your neck and shoulders. "Ahhh, I swear I'm coming back to life..." She murmurs softly.

"Get off of me. You're damp with sweat," you utter absentmindedly before taking a sip from your juice box.

"Hey, let me have this!" She grumbles cutely with a pouty expression, poking your cheek.

Kana Arima and Mem-Cho look on in shock, before Kana steps up, yelling. "WHAT THE HELL IS GOING ON HERE?!"

You're completely unfazed, still reading your manga.

Ruby's eyes widen in surprise, though she doesn't detach from you as she looks at Kana. "Whoa, you startled me. What's with the yelling out of nowhere?" She asks in a confused, innocent tone which seems to incense Kana even further.

"WE'RE the ones startled here!" Kana responds, leaning forward indignantly. "Ever heard of personal space?!" She points accusingly. "You two are stuck together like GLUE!"

You regard Kana, your expression completely aloof.

Ruby looks at her curiously, her cheeks slightly pink, eyes shining. "Oh! You know how onii-chan and I have been fighting lately?" She begins as she unwraps her arms from around you and makes her way around the couch. "Well, we made up the other day,"

She plops sideways onto your lap, wrapping her arms around your neck, clinging tight to you as she looks at Kana with a determined expression. "...And now we're making up for lost time!"

You turn the page on your manga.

"More like OVERCOMPENSATING!" Kana replies, her tone a mixture of anger and surprise before taking on a pleading, panicked tone. "You're part of the problem, Aqua! Tell your sister off!"

"I could do that," you begin in a distant, aloof tone, "or I could just let her do whatever she wants."

Kana slumps in defeat. "Right, I forgot...he's a total siscon..."

Ruby's legs kick happily beside you as she leans in and nuzzles your cheek again, her tone indulgent, "We've always been thick as thieves~"

Kana bares her teeth. "Egh...get off of him alrea-!"

Kana's voice trails off into a horrified gasp as suddenly Mem-Cho yells. "HOLD IT!"

"They're two hot twins that look hot together!" Mem-Cho continues, her eyes sparkling as she makes photo-frame gestures with her hands at the two of you. "Lemme take pics for my Insta!"

Suddenly, her phone is in her hands, and she's taking dozens of photos per second. Kana sighs in exasperation, looking with disapproval as she utters, "Ugh, you engagement junkie..."

Later that night, after Kana and Mem-Cho have left your house, midnight has come and you prepare for bed. You're standing on your balcony, hands on the railing, your aquamarine eyes contemplating the full moon parting the clouds in the horizon.

"Sensei...?"

Ruby's voice whispers softly behind you. You look back over your shoulder to see her in her pajamas. It's a short-sleeved form-fitting white blouse, a pair of lacy slightly translucent white panties, and nothing else. Her fair skin is glistening faintly under the moonlight, her hands clasped bashfully behind her back.

"...I'm sixteen now," she finishes her soft susurration with a proud smile and head tilt, a gust of gentle wind making her hair and her blouse billow like ocean waves.