My Little Sister Can't Possibly Be This Cute

Jiang Yu, who had just drifted off to sleep, was roused by the urgent ringing of the doorbell. Forcing his eyes open, a dull confusion clouded his gaze. He attempted to rise, but his limbs felt like rusted machinery untouched by oil for years—every slight movement produced a grating, metallic sound that made his teeth ache.

The doorbell shrilled again and again, growing more insistent, perhaps because the visitor had waited so long without an answer. But pitifully, barely ten seconds after Jiang Yu managed to open his eyes, his brain, on strike, ordered them shut again.

He was powerless against this deep, physiological demand and was ready to slip back into unconsciousness. The culprit behind it all was the light novel—“Love Metronome”—lying beside his bed, a book by an author whose name was utterly unfamiliar to him: Kasashiko.

He’d only meant to pass an hour with it before sleeping, assuming it would be the sort of light novel teetering on the brink of cancellation yet clinging to publication. But once he started, he couldn’t stop, and ended up reading all five volumes straight through the night. Before finally drifting off, Jiang Yu had muttered, “How could it be Sayuka?” and “Kasashiko is incredible!” and so on.

Now, the consequence was Jiang Yu sprawled on his bed, as limp as a puddle of mud.

The doorbell ceased its clamor. Just as Jiang Yu was about to sink into sleep, his phone rang on the bedside table. He struggled to sit up, frowned at the unfamiliar number, and answered.

Before he could speak, a sweet voice chimed, “Brother?”

Jiang Yu jolted awake. Heaven knows what strange potential was stirred in him—a former little-sister enthusiast with no sisters—by this sugary “Onii-chan.”

For a moment, Jiang Yu felt a surge of strength—if only. He replied, “Who is this?”

His voice was hoarse beyond belief, shocking him. He vowed never to repeat such a stunt again; his body felt utterly depleted, and he hadn’t even done anything!

“Eh? Brother, can’t you recognize Umaru’s voice? What’s wrong with your voice?!”

Umaru? Jiang Yu searched his memory and finally recalled. Umaru Doma, his uncle’s daughter. As a child, because of his mother, Jiang Yu often visited his uncle’s house, and the girl named Umaru was always trailing behind him like a little shadow.

They were childhood friends and cousins, but after Jiang Yu’s mother passed away, he lapsed into a period of despondency and rarely visited the Doma household. Still, he and Umaru often chatted on LINE; he remembered recommending her a few anime, though whether he’d succeeded in converting her was unknown.

Jiang Yu swallowed, his throat dry and eyes burning.

“Ah… so it’s Umaru. It’s nothing, I just slept late yesterday. Why are you calling?”

No sooner had he spoken than urgent stomping sounded on the other end, echoed by synchronized footsteps outside his door.

Realizing something was amiss, Jiang Yu hurriedly tried to hold the phone away, but suddenly, a voice pent up for too long erupted, “It’s because you’re a dumb brother and won’t open the door!”

“Uh… wait, just a moment, I’ll come right away.”

Jiang Yu rubbed his throbbing head and rushed to answer the door.

Outside stood a flawless beauty.

Clad in a school uniform, her flaxen hair cascaded down her shoulders, and her large eyes, usually lively and mischievous, now brimmed with dissatisfaction and reproach. The girl, bright-eyed and with pearly teeth, puffed her cheeks like a little bundle of resentment, as if her face were inscribed with “I’m angry, come comfort me.”

Hm? Come comfort me?

My little sister can’t possibly be this cute!

Jiang Yu hesitated, then, as if by reflex, raised his hand to gently rub Umaru’s head, saying, “It’s my fault. Please forgive your silly brother, dear sister?”

He froze the moment he spoke—was his relationship with Umaru really this close? He was merely acting out of habit. Hey, his previous self must have been a little-sister enthusiast, right?

Umaru immediately bowed her head obediently, letting Jiang Yu pat her, murmuring, “Then Umaru will forgive you this time.”

She looked up, her eyes shining as she gazed at Jiang Yu.

Umaru’s signature obedience? Jiang Yu forcibly suppressed his urge to make a joke, feeling as if he’d been healed by the smiling girl before him.

He suddenly understood what he should do now.

Jiang Yu smiled, nodding as he said, “Yes, yes—Umaru is the best. Umaru-chan is truly an angel.”

Huh? That line sounded familiar—just his imagination?

“Hehe~” Umaru grinned foolishly.

After standing around for a while, Jiang Yu finally came to his senses. He noticed the suitcase at the girl’s feet, picked it up, and carried it inside.

“Come in, Umaru. Just grab a pair of slippers for now.”

“Thank you, brother.”

…

Jiang Yu and Umaru sat facing each other. Freshly steeped tea steamed between them, wisps of vapor curling and rising in their gaze. Sunlight streamed through the window, illuminating motes of dust dancing gracefully in the air.

After a quiet moment, Jiang Yu asked, “Why did you come here?”

Umaru propped her chin with one hand and tucked her hair behind her ear with the other. The simple gesture, paired with her delicate features, had a startling charm.

With a mischievous smile, she said, “I came to ‘seek refuge’ with you, brother~”

Jiang Yu chopped his hand down in mock sternness. “Speak plainly.”

“Alright… The school I’m enrolling in is close to your place, so I talked it over with Mom, Dad, and Uncle Jiang, and here I am!”

“Huh? How did you convince your parents?” Jiang Yu remembered Umaru’s parents as being very strict, not even allowing her to stay out late, let alone live away from home.

“How? I just said I’d stay with you and you’d take care of me, and they agreed right away,” Umaru replied, puzzled.

Wow… Jiang Yu was surprised—were the Domas really so trusting?

Lost in astonishment, Jiang Yu failed to notice the slight awkwardness in Umaru’s tone and her evasive gaze. After all, whether his former self or his current, he was just an otaku, only differing in degree. Expecting a socially awkward nerd with few friends to be adept at reading people… Well, wasn’t that asking too much?

After a moment’s contemplation, Jiang Yu, though still surprised, accepted her answer. His last memory of meeting Umaru’s parents was in elementary school; they seemed to have liked him then.

“Alright, you can stay in the spare room. I’ll help you move your luggage in. Later, let’s go eat and buy you some essentials.”

He carried Umaru’s suitcase into the vacant room.

“Yay~ I love you, brother!” Umaru chirped.

Though Jiang Yu lived alone, his family didn’t give him any trouble. His apartment—two bedrooms, one living room, one bathroom, with an open kitchen and a small study—was quite decent for Chiyoda, Tokyo.

Naturally, Umaru would take the spare bedroom.

While Jiang Yu was tidying up for her, Umaru wandered into his own room, peering about as if searching for something.

Passing by his bedroom with some items, Jiang Yu noticed her and asked curiously, “Umaru, what are you looking for?”

Umaru replied matter-of-factly, “Of course, I’m searching for the magazines and comics every boy hides in some corner.”

Jiang Yu’s mouth twitched as he rubbed his forehead, sighing, “There’s nothing like that here, you fool. Get out!”

As it happened, his former self was apparently obsessed with ethics, believing that anyone under eighteen shouldn’t touch games or anime marked “18X.”

But… this character seemed oddly familiar. Did he have like-minded friends?

“Hehe…” Umaru laughed awkwardly and skipped out of his bedroom.

In short, before they headed out, the atmosphere in the house was harmonious and friendly (?).