The TV anime Marronier Oukoku no Shichinin no Kishi is set to premiere on NHK ETV on October 3, 2026. The opening theme has been revealed as yama’s “Sayonara wa Iwanai,” and a second promotional video featuring the song has been released. Additionally, the second batch of new cast members has been announced, including Sakurai Miyuki, Fujiwara Natsumi, Koyasu Takehito, Okitsu Kazuyuki, and Namikawa Daisuke, along with their comments.
Marronier Oukoku no Shichinin no Kishi is a fantasy romance manga by IWAMOTO Nao, serialized in Shogakukan’s Monthly Flowers since 2016. Set in the Marronier Kingdom at the center of eight nations, the story follows seven brothers who are knights dispatched as ambassadors to each country, where they seek their destined partners. The manga topped the female category of Kono Manga ga Sugoi! 2018 and celebrated its 10th anniversary in 2026. Its epic world-building and delicate emotional portrayal have moved a wide range of readers, and the work has been translated and published in Europe and Asia as well.
Opening Theme: “Sayonara wa Iwanai” by yama
The opening theme is performed by solo singer yama. Kameda Seiji participates as music producer, with lyrics and composition co-created by yama and Kameda. The song is specially crafted to enrich the world of the anime. Both yama and Kameda have shared their thoughts on the track.
The newly released PV2 showcases the gentle, warm atmosphere of the Marronier Kingdom and features the first individual voice performances of the seven brothers. In the latter half of the video, viewers can get an early listen to “Sayonara wa Iwanai.” The melody and lyrics are deeply linked to the story, vividly portraying the melancholy of departing from their homeland and brothers, as well as their strength to move forward.
Additional Cast Announced
The second wave of cast members has been revealed. Sakurai Miyuki voices Eleonora, a female knight and childhood friend of the seven brothers; Fujiwara Natsumi voices Princess Brunhilde of the Marronier Kingdom. Koyasu Takehito plays Eliot, Eleonora’s father and the castellan, while Okitsu Kazuyuki plays Hugo, the chancellor. Namikawa Daisuke voices Peregrinus, the father of the seven brothers.
Cast and Staff Comments
yama
“Marronier Oukoku no Shichinin no Kishi is a work that touches the heartstrings; after watching it, I felt a gentle warmth in my heart. I worked on the music together with Kameda Seiji. Imagining the same scenery, we carefully shaped the song, and it was a wonderful time. After some time passed and I listened to it again, I felt that beyond being music that accompanies the work, it will become a song that will be by my side in many scenes of my life. Meetings are always followed by parting, no matter the form. But even if we part, the time we spent together is a beautiful gift. ‘Sayonara wa Iwanai’ is not a word to refuse farewell, but a warm prayer that even if we cannot meet again, the presence and the gift remain in our hearts. I am glad that thanks to this work, I was able to create a precious song. I hope you enjoy it alongside the story.”
Kameda Seiji
“I have always loved yama’s voice. When yama contacted me about co-writing the theme song for the anime adaptation of this popular comic, I was overjoyed. We read the original work thoroughly and carefully crafted the song with the image of the animation in mind. The recording members also love yama, and it was wonderful to hear ‘Yama-chan!’ and the musical conversation start in the studio. I hope ‘Sayonara wa Iwanai’ becomes an important song for everyone.”
Sakurai Miyuki
“I will be voicing Eleonora. I was deeply moved by the pure feelings and delicate emotions within this grand fantasy world. Every character is lovable. The calm yet fluttery atmosphere between the sleepyhead and Eleonora is something I adore, and I hope to convey it to everyone through the anime. As a fan myself, I can’t wait for the broadcast. I hope many people will watch it.”
Fujiwara Natsumi
“When I read the original work, I thought it was a wonderful and fascinating story, so when I was offered the role of Brunhilde, I was truly surprised and very happy. Thank you! Of course, the stories of the seven brothers are wonderful, but I hope you enjoy the heartwarming exchanges between one of the brothers, the ‘cold-guy,’ and Princess Brunhilde. What is this itchy feeling?! It’s a wonderful work. Please watch it!”
Koyasu Takehito
“He’s an absent-minded old man, not seeming very motivated. Surely he’s not a bad person. One day, you’ll find yourself unable to take your eyes off him, because he’s cute (laughs). In this work, the minor old men characters are also very charming, so please pay attention to them as well. See you!”
Okitsu Kazuyuki
“I’m voicing the chancellor. I hope you enjoy the adventures of the knights of the Marronier Kingdom along with me. I’m in the studio with a fluttering heart every time.”
Namikawa Daisuke
“This work gives a wonderful illusion of stepping into a fairy tale. The environments and relationships surrounding the diverse characters are intriguing. And what exactly is Peregrinus’s existence? He’s quite mysterious. Is he just a memory, or is there something more? Please watch the broadcast to find out.”
Broadcast Information
Marronier Oukoku no Shichinin no Kishi begins on NHK ETV on October 3, 2026. It will air every Saturday from 6:25 to 6:50 p.m. Simultaneous streaming and catch-up delivery are planned on NHK ONE.
