Soshi Island Adventures is basicly a chapter for each member based on fairy tale. Some of them are based on their concept for The Boys. Here's the fairy tales:

TaeYeon: Rapunzel

Tiffany: Little Mermaid 

Jessica: Little Red Riding Hood

SeoHyun: Snow White

Yuri:  Cinderalla

Yoona: Beauty and the Beast

Sunny: Aurora

HyoYeon: Jack and the Bean Stalk

Sooyoung: The Nutcracker