Chapter 1

Shun lost his parents in a tragic accident when he was ten. They were involved in a fatal traffic collision, with a truck crashing into their car. His father was crushed in the front seat, while his mother's neck snapped from the impact. Miraculously, Shun survived with only minor injuries, but his parents perished instantly.

At such a young age, he found himself orphaned without any relatives willing to care for him; it was simply too inconvenient for them. However, a close family friend, with six members of their own, graciously welcomed Shun into their home. They expressed their condolences over his loss and offered to take him in as their own, despite not being related by blood. When Shun asked if they were sure about it, they reassured him that they were more than happy to have him join their family, especially since they had always wanted a son.

That day, Shun officially took on the name Morikawa Shun.

They embraced him warmly as part of their family. While he never forgot his original family, they helped fill the void in his heart.

The eldest sister, Morikawa Natsumi, treated him with genuine kindness, acting like a true older sister. Like their mother, she was warm and always protective of Shun. Among all the siblings, she was the most sisterly towards him.

The second eldest, Morikawa Chinatsu, was the same age as Shun but had a somewhat snobbish demeanor compared to her sisters.

The third sibling, Morikawa Nao, remained indifferent to Shun, often staying in her room, which led to few interactions between them.

The youngest, Morikawa Mafuyu, also appeared indifferent, though Shun felt her aloofness might be more of a kuudere nature. She seemed detached not only from him but also from her parents and siblings.

These were his new sisters.

His new mother, Morikawa Hinata, embraced her role with genuine warmth and care. She acted more like a mother to Shun than his biological mother ever had, as his real mother was rarely home due to her demanding job.

The family consisted of six members, including the father, who had sadly passed away three years ago from pancreatic cancer at the age of 45.

Shun mourned his loss deeply. Although he wasn't Shun's biological father, he had become every bit a father figure to him. Not only did he take Shun into his custody, but he also made him feel the warmth and security of a family once more. This profound bond compelled Shun to swear on his foster father's grave that he would always protect the girls for him, honoring the legacy of the man who had given him a second chance at family.

Three years after his passing, Shun had reached the age of 21 and was now a third-year student in the architectural program at university. Coincidentally, Chinatsu was also enrolled in the same course, which sometimes led to them being assigned tasks together, such as grocery shopping.

The supermarket was bustling with the usual evening crowd. The harsh fluorescent lights cast a cold glow over the aisles, making the frozen meat section feel even more frigid. Shun meticulously examined the different cuts of meat, oblivious to the irritated sighs of Chinatsu.

"Ugh, why must we do this together?" Chinatsu sighed, trailing behind Shun who meticulously inspected cuts of frozen meat. "Can't you manage this alone?"

"I understand you'd rather not be stuck with me," Shun replied calmly, "but could you imagine me trying to haul all this on my own?"

"You're a man, Shun," Chinatsu stated matter-of-factly. "You should be able to handle this. It's because you lack initiative that you can't even manage something as simple as shopping on your own. That's probably why you're still single."

"It's not like you're in a position to criticize my single status, are you? You're single too."

"I'm fine with being single. It's more socially acceptable for girls, after all," she replied. "But for guys to not have a girlfriend even after turning 20 is really embarrassing."

"I don't find it as embarrassing as you're making it out to be."

Shun wasn't particularly eager to dive into a relationship at this stage in his life. He felt that perhaps he wasn't ready for any romantic entanglements at all. Firstly, he needed to complete his college education. Secondly, there was the promise he made at his foster father's grave three years ago. It might have been easy to forget since time had passed, and the four girls were now adults capable of taking care of themselves. However, out of deep gratitude to his foster father, that promise meant everything to him. As the sole male figure in the family now, he felt a profound responsibility to protect and support them.

After they finished shopping, they headed home. Chinatsu remained aloof and walked three steps behind Shun, absorbed in texting on her phone. Despite Shun's repeated warnings about the dangers of distracted walking, Chinatsu always brushed him off.

Shun wondered when this distant and snobbish attitude toward him had begun. He and Chinatsu had been close childhood friends long before becoming siblings. Chinatsu used to enjoy playing with him, but something had changed after they became siblings. He couldn't understand why.

Upon arriving home, they were greeted by Morikawa Hinata, Shun's foster mother. Unlike Chinatsu, whose hair was dyed a golden blonde and had a gal-like appearance, Hinata exuded warmth with her gentle smile.

"We're back," Shun and Chinatsu announced in unison.

"Welcome back," Hinata replied warmly.

Shun and Chinatsu quietly organized the groceries they had bought, each placing items on their designated shelves. They didn't exchange a word and worked in silence. After a while, they retreated to their respective rooms.

***

When Shun entered his room, Mafuyu was there, lying belly-down on his bed, engrossed in a novel. She kicked her legs back and forth, clad in black and white striped socks. Among all the sisters, she was the quirkiest and youngest. With her doll-like appearance and black hair styled in twin tails, she had a penchant for Gothic Lolita attire, making her stand out as the most eccentric.

"What are you doing here again, Mafuyu?"

Mafuyu had been visiting Shun's room frequently lately. She had shown little interest in accepting him as part of her family, nor had she outright rejected the idea. Her reaction, as far as he could tell, remained neutral.

Seeing her in his room almost every day made her quirks even more apparent than usual.

"Reading a book," she replied in her typical detached, almost emotionless manner. Mafuyu was always deadpan and rarely showed any expressions on her face. She epitomized the definition of a Kuudere.

"Um, why in my room, though?"

"Because your room provides the most suitable environment for me to read," she replied calmly.

Shun wondered briefly what exactly made his room so conducive for her, but he dismissed the thought. It was Mafuyu, after all; her actions rarely made sense.

"Anyway, you should continue reading in your own room. I'm quite tired from studying, so I'm heading to bed now. There's not enough space for both of us in that small bed."

Mafuyu glanced at him briefly, then swiftly sat up on the bed and landed on her feet in a single motion before darting out of his room.

"Is she acting even stranger than usual?" Shun wondered for a moment, but then he shook his head. "Nah, maybe I'm just imagining things."

Shun proceeded to undress and change into his casual clothes. Before getting into bed, he noticed some stains on the sheets, one of which appeared to be from spilled water judging by its appearance.

"That damn Mafuyu. Did she just spill some water on my bed? She should be more careful when she's messing around in someone else's bed," Shun muttered as he proceeded to change the sheets.

Unbeknownst to Shun, it wasn't water that had been spilled. Furthermore, he hadn't realized that Mafuyu wasn't reading an ordinary novel—it was an erotic novel. Shun wouldn't discover this fact, at least not for the time being.