Hanasaki Futaba (花咲双葉 Hanasaki Futaba?) is Tsubomi's baby sister who appeared in the final episode of Heartcatch Pretty Cure!.
In episode 43, Mizuki was sent to the hospital. Youichi and Tsubomi were worried about her and ran to the hospital. When they see Mizuki and Kaoruko, Mizuki announced that she is pregnant shocking Youichi and Tsubomi. Tsubomi asked if it was a boy or girl. Her mom doesn't know but told Tsubomi she is going to be an older sister making Tsubomi happy. Mizuki is staying in the hospital until her new child arrives.
Futaba is born sometime before the final episode of the season, in which she is shown as a month-old baby, as Erika pokes her cheek before she and Tsubomi head to school.
Hanasaki (咲?): Hana (花?) means "flower" while saki (咲?) means "bloom". Together, Hanasaki stands for "blooming flower".
Futaba (双葉?) means "bud" or "sprout".