Tonagura!

Kazuki spent ten long years counting down the days until her childhood neighbors finally returned to the house next door. She has always harbored a crush on Yuuji, regarding him as her very first love—yet she never mustered the courage to confess before his family moved away. As children, Yuuji was a frequent playmate, often joining Kazuki, her older sister Hatsune, and his own sister Marie for games and adventures. However, her idealized memory of him comes crashing down the moment they reunite, as the real Yuuji proves to be far more forward and perverted than she ever anticipated. With both sets of parents away in South America, the two families are thrown together under one roof, forced to navigate daily life side by side while attempting to revive the innocent bonds of their shared past. Complicating matters further, their reunion takes an even more chaotic turn when they discover they now attend the same school.