Seiji is [Megumi's](https://anilist.co/character/87923/Megumi-Aino) neighbor, and childhood friend, thus Seiji understands Megumi's weak and good points. He reveals that he has a secret crush on her, which Megumi herself is completely oblivious to.

Seiji appears to be calm, friendly, and noble. Seiji admires the way Megumi helps out people, and how cheerful she is. He has a strong sense of justice and will always lends a helping hand to those in need. 

(Source: Pretty Cure Wiki)

All around the world, Pretty Cures have been fighting against the invasion of an enemy known as Saiark. Shirayuki Hime, the princess of Blue Sky Kingdom, is a Pretty Cure; but unable to defeat the enemy alone, she falls behind the others, and ends up in a bad situation. 
On her quest to find a partner, she meets Aino Megumi (Cure Lovely), and the two join forces to battle the enemy together. They learn that by assembling all PreCards, you can get any one wish fulfilled, and they team up with the fairy Ribbon to protect world peace, transform, and dress up as they fight! 
A new Pretty Cure story with a dress-up theme begins!

The film’s story is set in the Doll Kingdom where dolls dwell. In the story, the Pretty Cures are watching a doll play about to start, when the dolls suddenly start talking. “Please rescue our kingdom!” the ballerina named Tsumugi says, and she leads the Pretty Cures to the Doll Kingdom. There, the Pretty Cures thought they would be surrounded by cute stuffed animals, but instead they find a mysterious man named Black Fang who is attacking the kingdom, and he captures Tsumugi. The country normally filled with happiness is hiding a sad secret, and the Pretty Cures must help save the day. 
(Source: Pretty Cure Wiki)

A spring carnival held in the country of dance and song, Harmonia, is beginning. Haruka Haruno and her friends also join the festival to learn dance and song from their senior Pretty Cure warriors. However, the fairies go missing, and the carnival is thrown into confusion. Even worse, the announcers Odoren and Utaen seem extremely suspicious, and the guardian dragon of Harmonia has started a rampage, angry at the chaos at the carnival. In order to protect the peace of Harmonia, the 40 Pretty Cure warriors work together to create a miracle through dance and song filled with hope.

The film's story will revolve around the power that lies in the tears that the Precures hide. The video reveals that the Precures' tears have the power to end the world, and so the Precures must not cry no matter what. The Precures will fight in the world of song and magic to protect their tears. 
 
(Source: Anime News Network)

A movie celebrating the 20th anniversary of the Precure franchise, featuring characters from all 20 series so far!

Seiji Sagara