Members of the Imperial royal family greeted visitors from the balcony of the Imperial Palace in Tokyo yesterday on the emperor’s 63rd birthday.
Empress Masako arrived in a vibrant blue velvet pillbox.
Princess Aiko wore a blush silk covered hat with short, upturned Breton brim trimmed with a triple pleated, draped hatband and bow at the back. It’s a piece that at closer view, I suspect, would show exquisite balance and beauty.
Designer: unknown
Previously Worn: This hat is new
Crown Princess Akiko repeated a bumper hat covered in pale citrusy green patterned silk jacquard.
Designer: unknown
Previously Worn: Dec 23, 2015
Princess Kako repeated a draped turquoise silk bandeau headpiece trimmed with a folded side bow appliqued in the same beaded lace as her gown.
Designer: unknown
Previously Worn: Jan 13, 2023; Jan 18, 2022
It’s lovely to see this tradition return for the first time during Emperor Naruhito’s reign.
Images from Getty as indicated
Royal Hats 
Elegant and classic as ever! Empress Masako arrived at the palace in a matching hat to her gown, but removed it. How unfortunate.
https://www.gettyimages.com/detail/news-photo/emperor-naruhito-and-empress-masako-are-seen-on-arrival-at-news-photo/1469019480?adppopup=true
Just to clarify Jimbo, in that photo Masako is wearing a hat to visit Ahikito and Michiko at a different palace, but she didn’t wear it at the Imperial Palace because that’s where she lives. The ink blue color is fantastic for the Empress, and the hat, while a standard shape (and of unknown, if any, trim), is still wonderful on her. Thanks for your sleuthing as always and finding this bonus!
As for the rest, Aiko’s reminds me of some hats Princess Akiko of Mikasa has worn, and overall it’s a good look for her. Of course, I enjoyed the bright colors on Kiko and Kako.
I was a little sad this was such a pared down group present for this occasion, but glad we still got some nice hats.
Jake, thanks for the clarification. I know the “rule” about wearing a hat in one’s own home . . . I just figured they were returning home from Home Depot, or maybe breakfast at Bob Evans. HAHA
More photos of Masako’s hat show some decoration on the side. She added the hat to visit the Emeritus couple at Sento Imperial Palace in the afternoon. She didn’t wear a hat for earlier events at the Imperial Palace.
Aggravatingly photos for hat-lovers since they’re are too distant (and through a window!) to show much. As you’ve said, HQ, they’re likely to be exquisitely made. It looks as though Aiko’s may have some chiffon pleating to echo her sleeve and neckline detail — lovely.