Amy Yuuzuki, referred to as Ami-neesan, is the great-granddaughter of Daigo Kiryu. She is a reliable older sister figure to Daigo, frequently assisting him in overcoming his shyness. Amy's free-spirited, rule-bending tomboy nature resonates with Daigo. In the series conclusion, Daigo expresses his return was for Amy and her melody, culminating in a heartfelt hug.