I Became Hibari's Frail Younger Sister

[Check out my upcoming story, Bound to a Breakup System] She was absolutely certain that she had transmigrated. Because she was inside her mother's womb. After she was born, she saw a little baby. "Hibari." In short, Hibari had become my older brother. At the same time, a "Villain System" bound itself to my mind. You want me to be a villain? Are you trying to get me killed? Villain System: As a qualified villain, do you know what you need to do? Qiansui An: I get it, I get it. I have to kill the protagonist and become the coolest person around! Villain System: No. A qualified villain has to be patient, secretly cause trouble, and make the protagonist's group trust them. They must never reveal that they're the villain. They also have to become incredibly powerful to help the protagonist grow, then get killed by the protagonist in the final battle for saying one thing too many. Got it? Qiansui An: ?... Got it. But can I at least have a normal body? Hibari's younger sister is beautiful, gentle, and frail, like a rose growing in the wind with its thorns snapped off. From the moment she was born, everyone was destined to cherish her. But she can barely walk. All you can do is watch her fall, quietly get back up, and smile at you again. He thinks that, for the rest of his life, he will have to protect his little sister. But she dies in her teens, amid the bloom of youth, and everything withers from then on. After that, he waits ten years for her. They have no idea that Qiansui An knows the plot inside and out. When she sees the protagonist's group as little kids, she turns into their biggest fan. But the System wants her to cause trouble. Qiansui An drags her frail body around causing trouble. Who could have guessed that everyone would look at her with pity instead? "She must be innocent." "She must be suffering so much right now." "Poor thing." Qiansui An: Listen to me! I really am a villain! In the end, Qiansui An completes the System's mission and successfully returns home. Who could have expected her to transmigrate again, this time ten years into the future? [Ding! Hello, dear Host. I'm the Matchmaking System. You need to bring couples together to complete your missions!] Qiansui An: ? So you're messing with me! ☆☆☆☆☆ ★ A slow-paced, cozy, healing story. It's a very long novel, with lots of everyday life and original characters besides the heroine. Since the heroine has to play a villain, she'll have underlings. ★ The timeline goes from early childhood to middle school, then ten years later. ★ An absolutely over-the-top, sweetly kind little sister with an overflowing Sky attribute. Even as a little kid, she isn't childish at all. She's an exceptionally obedient and sensible sweetheart, trading sincerity for sincerity, but she's also a Mary Sue, very much so. ★ The main fandom is the Vongola family, with Bungou Stray Dogs and Jujutsu Kaisen as secondary fandoms. A few other series might pop up here and there, but they won't affect your reading. ★ The little sister was adopted by the Hibari family. The System is her golden finger, and it's a very powerful one. ★ My take on the characters, extremely out of character, with lots of headcanons and a muddled timeline. Upcoming story: Bound to a Breakup System "I'm the Breakup System. As the name suggests, you first fall in love, and then break up." Xinghai Xing: "..." So what's the point of falling in love? Xinghai Xing is always saying there's nothing worth pursuing in romance these days and that she'd rather focus on her career. By chance, she binds herself to a Breakup System, whose missions require her to fall in love at least twice in each world and then break up. Xinghai Xing: I can't do sweet romance at all! Jujutsu Kaisen: As the daughter of the Star Religious Group's leader, Xing acts diligently to usurp the position of her wicked, good-for-nothing adoptive father. Along the way, she starts dating a certain curse user. But three months later, Xing resolutely breaks up with him. Geto spends the most romantic, wonderful, happiest three months of his life immersed in the beautiful dream Xinghai Xing has woven for him, unable to pull himself away. Then the dream shatters. Six months later, Xing runs into him at a dessert shop, together with her new boyfriend, the newly anointed Six Eyes user. "Xing..." "Long time no see." Demon Slayer + Jujutsu Kaisen: A thousand years ago, Xinghai Xing was a doctor. Xinghai Xing is determined to study medicine and become a renowned doctor, but she hits the biggest setback of her life at the Ubuyashiki estate. She studies hard and pores over books to find a cure for him. Just as she's beginning to make progress, that jerk destroys all her research. Xing: "..." Breakup! This is definitely a breakup! Six months later, Xing runs into Muzan, now a demon, while out with her new boyfriend, the newly crowned King of Curses. "Xing." "I've found you." Detective Conan: Xing is a nobody in the Black Organization. While secretly working undercover, she accidentally becomes the boss of the Black Organization, and also starts dating a certain white-haired man. Three months later, Xing breaks up with him. Six months later, Xing runs into her ex-boyfriend at a cafe while out with her new boyfriend, a dark-skinned man. "Xing..." "Nice work." (Through gritted teeth.) Hunter x Hunter: Xing is born in a small village with hardly any men, so she decides to try online dating. Her boyfriend knows just what to say, but never sends a photo and is a bit stingy. They break up after three months of online dating. Six months later, Xing takes the Hunter Exam with her new, younger boyfriend and hears her ex-boyfriend's voice. Oh, wow. They're brothers, of all people. He gazes at her with dark eyes and says, "Xing." "This isn't right." Bungou Stray Dogs, K, Haikyu!!, The Prince of Tennis, Katekyo Hitman Reborn... More worlds will be added as the story goes on. Theme: Treat the world with kindness.