Bernie (called Nouveau in Japanese) is a talking dog serving as an emissary from the Flower Planet's King. He and his partner, a talking cat named Cateau, are dispatched to Earth on a critical mission: locate a descendant of the Flower Star people who can find the legendary Seven Color Flower, essential for the rightful heir's ascension to the throne.

Identifying Lunlun in France as the sought-after Flower Girl due to her lineage, Nouveau partners with her once she accepts the quest. He accompanies Lunlun and Cateau on a journey across Europe and into Northern Africa. Throughout this adventure, Nouveau actively aids Lunlun in searching for the Seven Color Flower while helping people they meet along the way.

Their mission faces constant challenges from antagonists Togenishia and Yabouki, who repeatedly interfere with their efforts, seeking the flower for their own ambitions. Despite these obstacles, Nouveau remains a loyal and steadfast companion. He also appears in the theatrical short film *Hana no Ko Lunlun: Konnichiwa Sakura no Sono*, supporting Lunlun during a visit to Japan where they confront the same adversaries amid a crisis of prematurely falling cherry blossoms.