Kozue (renamed "Mila" in the German Version) had always been a frail and sickly child until she moved from the big City to a Suburban and in with her aunt and uncle in hopes to use the fresher air to help improving her ill health. It was then that she also (re-)discovered her passion for the sport of volleyball. From there on, she meets many loyal friends and comrades as well as powerful rivals and also suffers heavy personal losses along her way to become the Nation's Top Attack Player (hence the title).