**Chapter 1: Fractured Harmony**

The sun had just begun to set, casting a warm orange glow over the large house that Noa, Sara, Hanabi, Yui, and Aria shared. The sound of children's laughter and playful shouts filled the air as Karin, Mitsuki, Yuki, Susuki, Aya, Satsuki, and Rin played in the backyard. The seven adults had been in a polygamous relationship for a few years now, and their household was usually filled with love and laughter. However, beneath the surface, tensions had been simmering. In their bedroom, Aria and Hanabi were in the midst of a heated argument. Susuki, their 10-year-old ward, had been begging to spend the weekend with her friend, and Hanabi had expressed her concerns about it. Aria, however, was adamant that Susuki should be allowed to go. "I don't understand why you're being so stubborn, Hanabi," Aria said, her voice rising. "It's just a weekend. What's the harm in it?" Hanabi stood her ground, her eyes flashing with determination. "I'm just thinking about what's best for Susuki. She's been through a lot, and I don't think it's healthy for her to be away from us for an extended period." Aria's face darkened, and she took a step closer to Hanabi. "You're always so quick to disagree with me. Can't you just support me for once?" Before Hanabi could respond, Aria cut her off. "Get out of here, Susuki. This doesn't concern you." Susuki, sensing the escalating tension, quickly exited the room, looking worried. Aria's anger turned to fury, and she began to yell at Hanabi. When Hanabi refused to back down, Aria's anger boiled over into something more sinister. She pinned Hanabi to the bed, her strength overpowering Hanabi's protests. The scene was one that had played out before, albeit in different ways. Aria's strength was something that the others had grown accustomed to, but it didn't make it any less painful. Noa, in particular, had a tendency to turn a blind eye when Aria lashed out, a fact that often left the others feeling frustrated and helpless. As the argument escalated into something more violent, the sounds of the children's laughter and play outside seemed to fade into the background. The house, usually a sanctuary, felt suffocating and oppressive. Just as Aria's assault on Hanabi reached its peak, the bedroom door burst open, and Yui stormed in. Her eyes widened in horror as she took in the scene before her. Hanabi was crying, her clothes disheveled, and Aria's face was twisted in a snarl. "Yui, get out of here!" Aria snarled, her eyes flashing with warning. But Yui didn't back down. Instead, she strode over to Aria, her voice trembling with rage. "How could you, Aria? How could you hurt her like that?" Aria's expression turned cold, and she released Hanabi from her grasp. Hanabi scrambled off the bed, her eyes brimming with tears. Yui's gaze locked onto Aria's, her voice firm. "You're not going to hurt anyone else in this household. Not while I'm here." The air was thick with tension as Aria's eyes seemed to bore into Yui's. For a moment, it seemed as though she might lash out at Yui as well. But then, her expression shifted, and she turned away, her voice dripping with venom. "You have no right to question me, Yui. I am not accountable to you." As the scene continued to unfold, Sara, Noa, and the children were oblivious to the turmoil that had erupted in the bedroom. But it was only a matter of time before the rest of the household became aware of the fracture that had appeared in their once-harmonious relationship.