During their childhood, Hatsune and Kazuki Arisaka, and Yuuji and Marie Kagura grew up as neighbors, living in close proximity that they could easily get onto each other's second floor verandas. The quartet enjoyed each other's company, engaging in different fun activities, until the Kaguras had to move to a different place. After a decade, the Kagura siblings are coming back, but it seems like Yuuji has turned into a pervert and Marie is no longer the crying baby she once was!