Himari no Mawari

Sixteen-year-old Haruki Aizawa, a second-year high school student, prides himself on living a structured and efficient life. His carefully maintained routine is abruptly upended during summer vacation when a girl named Himari Aizawa suddenly appears at his door, cheerfully calling him her older brother. The unexpected arrival stems from his father’s recent remarriage; his new stepmother has a daughter of her own, making Himari his new stepsister. Complicating matters further, both sets of parents are currently working overseas, leaving the two teenagers to share the house entirely on their own. What begins as an awkward adjustment to a sudden blended family quickly takes on a different dynamic as they navigate daily life without adult supervision. Rather than keeping her distance in this unfamiliar arrangement, Himari proves to be remarkably determined to stay by Haruki’s side. She is strangely insistent on spending every possible moment with him, clinging to her new role as his little sister with unwavering enthusiasm. For a young man who values order and efficiency, adapting to Himari’s constant presence—and unraveling the reasons behind her intense attachment—becomes the most unpredictable challenge of his summer.