Seigaku Matsuri is the fourth episode of the Sekaiichi Hatsukoi: Propose-hen anime film. It is a sequel to the previous movie, Sekaiichi! In this movie, the star ship or kamikaze struck a shore to be saved by Matsubara, but he was in another world.
Hayate traveled to the parallel world with Yamato and Jessica and learned about Hayate's estranged relationship with Yumina, while still staying in touch with his best friend and Yumina's sister, Ritsuko. He and the two sisters headed to the Kyoto Park and then there visited many friends to continue the talks of the past.
On the day of the wedding ceremony, Hayate received a visit from the former rival Miyamoto Geishiro. The geisha requested the right clothing for Hayate and asked him to propose. Hayate accepted, and Miyamoto invited his best friends to attend the wedding ceremony.
After all the preparations were done, Hayate, Miyamoto, and Yamato met in the garden under a full moon. They were not permitted to speak a word until Miyamoto insisted on introducing himself and introducing the princess. Miyamoto went on to introduce Hayate's sister, Hayatomi.
Hayate was really worried that Miyamoto was going to propose, but he thought it would be better if he did not ask her if she was ready. Hayate finally told Miyamoto that he wanted to marry her, and he gave her a ring. But Miyamoto rejected his proposal, saying that he had not had a chance to get to know Hayate and how he feels about his family. Hayate was shocked by the rejection and accused Miyamoto of feeling bad because Hayate loved Yumina.
Before Hayate left, he told Miyamoto that he believed that he should choose the perfect bride. Miyamoto thought that he and Hayate would go on a journey together and would meet again. Hayate and Miyamoto parted on good terms.
The theme of the anime Seigaku Hatsukoi: Propose-hen is based on the story of the book "Hatsukoi" by Eiji Yoshikawa. In the anime movie, Hayate and Miyamoto are both from Kumamoto, and Mikanomiya Yumina is from Osaka. The Yumina sisters are older than Hayate and he and Yumina always had a rivalry between them, even during the wedding ceremony.
Later on, Miyamoto proposed to Hayate, but he declined. Yumina was the one who offered the ring to Miyamoto and the two were now good friends. Hayate then and in the last scene, Miyamoto proposed to Hayate and the two are now betrothed.