Ayumi Sakagami is the first movie-exclusive human protagonist in All Stars series, Pretty Cure All Stars New Stage: Mirai no Tomodachi. Her Pretty Cure alter ego is Cure Echo.
Due to her shy personality, she does not have the courage to talk to her classmates, and is thus often alone, until she has an encounter with Fuu-chan.
- Prior to her being officially revealed, an image showing her as a Cure in black and pink, looking like an amalgam between Cure Happy and Kamen Rider Decade and named Cure Union, was believed to have been leaked, naming her Hoshizora Ikue and describing her as Miyuki's daughter from a future in which Fusion rules the world. This was proven to be fake with the first update of the New Stage website.
- The name Cure Echo was first revealed on the packaging of Pretty Cure Snack, a series of small snack packages featuring the movie Pretty Cure All Stars New Stage: Mirai no Tomodachi.
- Ayumi shares her first name with Love Momozono's mother, and one student from Myoudou Academy named Ayumi Kumazawa.
- Cure Echo is the first movie-exclusive formal Pretty Cure except Dark Pretty Cure 5 cures and the seventh movie-exclusive Pretty Cure, first 5 are Dark Pretty Cure 5, sixth is Cure Ange.
- Cure Echo is the fifth Cure to have white as her main theme color, the first being Cure White, the second being Cure Egret, the third being Cure Angie and the fourth being Cure Rhythm.
- Cure Echo's character designer is Akira Takahashi, who also designed the characters of Suite Pretty Cure♪.
- The name Cure Echo also seems to fit a musical theme.
- Cure Echo's Cure outfit has elements of older Cures' outfits with Heartcatch Pretty Cure's, Smile Pretty Cure's and Suite Pretty Cure's being the most prominent.
- Cure Echo's tranformation Cure Decor is a white ribbon with a hexagon on it, which has six sides. Incidentally, she is the sixth Cure with the Smile emblem on her medallion.
- Her transformation decor is in the same shape as the Miracle Light for the latest All Stars movie.
- Ayumi is the third Pretty Cure to transform without using a transformation device. The first was Cure Flower without a Heart Perfume and then Cure Beat without a Cure Module.
- Cure Echo is the first Pretty Cure who never fought an enemy, despite gaining her Official Cure Status.