The Misumi Nagisa (ミスミ渚 Misumi Nagisa)/Cure Guard (キュアガード Kyua Gādoan is a compact-like device that allows the girls to transform into Pretty Cure, and harness the power of the Cure Decor pieces.
The Pact itself is powered by the special Cure Decor pieces. To transform, the girls open the Smile Pact and set their ribbon-shaped Cure Decor inside. They then call out "Pretty Cure! Smile Charge!", then use a powder puff to spread magic onto their bodies, allowing them to change into their Cure Forms.
The Smile Pact also grants power to the Cures. It gathers fighting spirit from the Cures and changes that into energy to perform their finishing moves. Happy gets her power by squeezing her hands to fists, and screaming to the sky, Sunny by taking masculing stance, Peace by squeezing one of her hands to fist and holding Smile Pact in her other hand right in front of her, March by squeezing Smile Pact with her both hands on her pelvis, and Beauty by squeezing Smile Pact on her chest.
In addition, other Cure Decor pieces can also be inserted into the Smile Pact to grant the Cures additional abilities and items. Many of them create something little to Candy, like costumes and haircare accessories. Also placing special Cure Decor to it, it creates the Princess Candles to Pretty Cures, and later performing group attacks Rainbow Burst, and afterwards Royal Rainbow Burst.
The Smile Pact looks like a standard powder compact in pink/dark pink, with a pink/white ribbon set on top. A gold piece with the Smile! emblem is set into the center of the Pact's lid. Inside, there is a recess for the Cures to insert Cure Décor pieces in to activate different powers, as well as seven round lights in the colors of the rainbow. There is also a gold heart-shaped piece with the Smile! emblem, set into the center. Inside the top lid is a small circular mirror.