In her civilian form, Sei has golden blonde shoulder-length hair held up in two orange barrettes with cream-colored cloth decorating them. Her flowing top is also cream-colored and has an orange color with a star necklace. The bottom part of her dress is dark brown, orange and purple with purple tights tucked into thigh-length cream-colored boots.

As Cure Twinkle, her hairstyle is similar to that of Cure Dream's and becomes blonde with orange streaks in the front. Her tiara is gold with a star in the center of it. She also wears a yellow choker and star-shaped earrings. Her dress is sleeveless and has light yellow and yellowish-green layers that cascade toward the left. The top is colored the same and has an orange ribbon with a gold brooch in the front as well as an orange belt with a star in the center. Her armbands are long and cream-colored and she also wears cream-colored wrist-length gloves with orange bands around them. Her boots are white and are thigh-length.

(Source: Pretty Cure Wiki)