Niina Aoyagi, an 11-year-old girl, believes she is in love with Atsurou Itami, a man 15 years her senior. In her previous life as Chitose Amamiya, she harbored feelings for the same individual during their middle school days. With a shared promise made before Chitose's passing, Niina strives to honor this commitment while keeping her cherished memories of the past concealed. Will Niina succeed in soothing the emotional scars that reside in both of their hearts?