Maki Matsudaira is the world's number one mother.

The gentle and beautiful glow of the evening sky shone down on the siblings as they made their way home.

“Big brother~”

“What is it?”

“Did you make any new female friends today?”

“Well, I suppose you could say I did?” Kiyomizu Matsudaira thought of the fujoshi upperclassman from the literature club.

“Eh?”

In an instant, Kiyoyuki Matsudaira’s eyes sparkled as she looked straight at her brother. “R-really? If that’s true, please bring her home so I can personally interview her—”

“...She’s just the president of my club.”

“So, that doesn’t really count as making a friend, does it?” His younger sister’s face fell, disappointment clouding her features.

Kiyomizu felt as if he’d done something wrong and hastened to say, “...Well, I’ll keep trying my best!”

“Mhm~” Kiyoyuki’s smile bloomed, her gaze gentle. “But don’t push yourself too hard. You’ve already started participating in club activities, and that’s a big step forward. You’re doing really well.”

“...”

Being praised by a sister two years his junior, Kiyomizu couldn’t help but blush.

“Joining a club is only the beginning. Things will get better from here! You’re moving forward, step by step, big brother! You’ve worked so hard. Truly, truly amazing.”

With a gentle smile, Kiyoyuki reached out to pat her brother’s head, then deftly snatched the plastic bag from his hands.

“What’s wrong?”

“As a reward for big brother, I’ll carry this today.”

“...Why do I get the feeling you’re treating me like a child?”

“It’s fine! Today, you can be as spoiled as you like.”

Bathed in the golden glow of the setting sun, her smile blossomed in the twilight of the shopping street like a narcissus—so pure, so beautiful.

...All right, I’ll try a little harder for you.

Kiyomizu smiled too, reaching out to ruffle her hair.

[After being patted on the head, Kiyoyuki Matsudaira’s affection for you has increased.]

How much affection did Kiyoyuki have for him, anyway?

He suddenly wanted to know. For his mother and sister, he liked to think their affection for him was at least in the seventy-one to ninety range—a bond you could entrust your life to.

But what about his sister...?

He opened the affection menu and checked.

[Character: Kiyoyuki Matsudaira]

[Status: Just had her head patted by her big brother, feeling extremely happy...]

[Affection: >100]

[Danger!]

That glaring red “Danger” character flashed before Kiyomizu’s eyes, leaving him utterly stunned.

Affection over one hundred?

What a dangerously high number!

He quickly checked the detailed analysis.

[Over ninety-one: Severe obsession, yandere tendencies...]

“Yikes!”

Kiyomizu sucked in a sharp breath.

“Big brother?” His sister tilted her head, looking at him with adorable curiosity.

“It’s nothing. I just feel you’re too good to me.” He kept a straight face.

“Of course! After all, you’re my most beloved big brother...” Her eyes sparkled like a puppy’s.

So cute—who could believe she was a yandere?

On the way home, Kiyomizu turned the thought over and over in his mind. No matter how he looked at it, he couldn’t see anything yandere about her behavior. She was just a little more affectionate than most sisters, but still within the bounds of normal sibling attachment—surely not obsessive... But the system couldn’t be wrong, could it? Was Kiyoyuki just hiding it so well, even he, her brother who lived with her day in and day out, couldn’t tell?

If that were true, she was a genius...

Kiyoyuki, oblivious to her brother’s thoughts, skipped home with light steps, her expression the very image of a girl in love.

Up ahead, the road sloped upward.

The Matsudaira home stood at the top of the hill.

By the time the siblings reached their house, evening had begun to settle in.

Their home was a three-story Western-style villa, complemented by a small garden in the Japanese style, its architecture echoing the Meiji era.

The yard was lush and green, the flowerbeds bursting with June’s blooms, teru teru bozu and wind chimes swaying beneath the eaves, and a wooden plaque inscribed with “Matsudaira” hung by the gate.

They crossed the garden and stepped inside.

The interior was tastefully decorated—not lavish or showy, but with a subtle sense of elegance.

It was clear this was a household run by women; a gentle fragrance lingered in every corner of the living room.

A photo of the mother and her two children hung on the wall behind the sofa.

“You must be hungry, big brother?” As soon as she slipped off her shoes, Kiyoyuki looked up at him. “Wait just a bit, I’ll go make dinner now.”

“I’ll help you.” Kiyomizu followed her into the kitchen.

His sister made her specialty curry udon, while he, seeing half a chicken in the fridge, prepared a pot of chicken soup and a fresh green salad.

“I’m home~”

Just as dinner was nearly ready, their mother returned.

The chicken soup bubbled on the stove. Kiyomizu was about to add salt when he heard his mother call from outside, “Kiyomizu, come protect me!” He set down the salt and hurried out to see what she needed.

The living room lights were off, leaving the room dim.

His mother stood at the entryway, watching the garden with wary eyes.

At the sound of his footsteps, she turned, a breathtaking smile curving her lips.

She was thirty-eight this year, but still looked young and beautiful.

Her face was delicate and pale, framed by thick, glossy black hair pinned up at the back.

Her eyes were long and alluring, with upturned corners and brows like willow leaves; her nose was high and straight, giving her an air of dignity.

Her lips were vivid and dewy, her gaze luminous and deep, radiating the mature, seductive charm of a woman in her prime.

She wore a tailored business suit that hugged her slender waist, her shapely, straight legs sheathed in black stockings—a look that exuded the poise of a career woman.

As for how stunning her figure was, Kiyomizu felt it best not to elaborate.

After all, this was his mother, Maki Matsudaira.

It wouldn’t do to linger on such details from a male perspective.

“Kiyomizu, come here quickly, you nearly scared me to death...” Maki clutched her chest, looking genuinely shaken.

“What happened?” Kiyomizu approached the entryway.

His mother grabbed his arm, half-hiding behind him, and pointed outside. “Look, there’s a snake!”

Kiyomizu looked beneath the cherry tree in the garden.

A slender snake, about a meter long, with pale yellow and black stripes, was coiled among the bushes.

“Is that a pit viper?” Maki’s voice trembled as she clung to her son’s arm.

—She was faking it!

“That’s a rat snake—harmless. The juveniles do look a bit like pit vipers, but there’s no need to be afraid...”

With that, Kiyomizu grabbed a broom from the entryway and stepped outside.

His mother, still clinging to his arm, followed him out cautiously.

“If you’re scared, why are you coming out here?”

“Even though I’m scared, I enjoy being protected by my son even more.”

“...Mother, I’m not sure I should say this, but...”

“Go on.”

“There’s a saying: ‘a son should avoid his mother, a daughter her father’—I think I’m at the age to start avoiding you... ow, ow, ow!”

“If you say that again, I’ll strangle you!” Maki warned fiercely, finally releasing the tender flesh she’d pinched at his waist.

The rat snake, sensing danger, looked up at them from the bush.

Kiyomizu used the broom to lift the snake’s body, then tossed it over the wall.

There was a small grove outside—the harmless snake would be fine there.

“Wow, Kiyomizu, you’re so brave!” Maki clung to his arm, looking at him with adoration.

“You’re such a bad actor—this is embarrassing!” Kiyomizu’s skin prickled with goosebumps.

“I’ve been working hard at the office all day, and finally I’m home. Can’t I have a chance to be spoiled by my son, just once?” Maki pouted and bumped him with her body in protest.

The sensation was soft and yielding, fragrant in the twilight...