Pretty Cure Mashup Team is simply a Precure Team consists of members who came from different seasons. Every year, as the Cures are added, the members of each Precure Mashup Team is added as well.
There are rules when joining the Precure Mashup Team:
1. The Cures must be in the Main Team of their shows.
2. No Cures from the same season can join the same Mashup Team, even siblings who are in the main team aren't exempted from this rule. (eg. Hana/Cure Yell and Emiru/Cure Macherie can't be in the same Mashup Team because they're both from Hugtto Precure.)
3. Every Cures must transform individually, especially those who can't transform without a partner in their shows. Reasons are in #2. (eg. Saki/Cure Bloom and Mai/Cure Egret don't need each other to transform anymore.)
The Trivia about Precure Mashup Team Series is:
1. Most Cures retain most of their personalities from their shows, even though they slightly change by the time their Precure Mashup Team Shows take place. Cures whose attitude is unlikeable by fandom have drastically changed into a better person.
2. Some lead Cures are the Protagonists again in their PMT Shows, while some aren't.
3. In the original lineup (2020), only Go Cheerful Crew, Joyful Girls Squad, and Angelic Team are the ones where none of their protagonists are the lead Cures in their respective shows.
4. Cures mentioning of other Cures outside of their respective PMT shows (usually the ones who came from the same season as them) is inevitable, yet they shouldn't be sighted as they aren't belong to the said PMT. (eg. Hibiki/Cure Melody, who now belongs to Joyful Girls Squad, can mention her Suite Teammates, but they mustn't be sighted as they have their own set of friends and shows now.)
5. The PMT Shows take place at least 4 years after the finale of each Precure Seasons. Therefore, those Cures who are 13-14 years old in their shows are now 18-19 (if their birthdays are celebrated in-series).
6. Those backstories and flashbacks that aren't been shown in the canon shows are now expanded. Characters who aren't also named in canon are now given a name.