Quiet, earnest, and a bit nerdy, Toyama Satoshi runs a marine plants store where he can indulge in his love for aquatic vegetation. Though he barely makes enough money, Satoshi is determined to hold on to the store as it fulfills a promise he made to his two best friends years ago. One day, a beautiful young model shows up at his steps asking for a job. As clueless as ever, it takes some time before Satoshi realizes that she is actually his childhood friend and first crush Karin. Though he doesn’t understand what has brought Karin to him so suddenly after thirteen years, Satoshi is glad to have her back in his life. Their happiness is short-lived though as they soon receive sobering news about their friend Yuji .
