志木さんち

Natsuki, Soushuu, and Touma are three brothers who live together and handle household responsibilities on their own due to their parents' frequent absences for work. They maintain a routine of supporting one another through everyday tasks and challenges. Their mother, Ume-ko, returns home unexpectedly after a prolonged period away. She introduces a young girl named Haruka as the brothers' blood-related younger sister. The four siblings start navigating their new family dynamic together. (Unreviewed summary by Grok 4.1)