Takehito Koyasu Wants You to Watch the Middle-Aged Men
The second wave of casting adds five actors, and Takehito Koyasu supplied the headline comment. He plays Elliot, the castellan of the Marronnier Kingdom and the father of the knight Eleonora. Koyasu (Zeke Yeager in Attack on Titan, Dio Brando in JoJo's Bizarre Adventure) describes the character as a spacey, visibly unmotivated older man who is definitely not a bad guy, and predicts viewers will find themselves unable to look away. The reason he gives is that Elliot is cute. He also asked fans to pay attention to the show's supporting adults in general, and called them surprisingly charming.
Kazuyuki Okitsu voices the chancellor, Hugo, and says he turns up to every recording session with his heart fluttering. Daisuke Namikawa plays Peregrinus, father of the seven brothers, and kept his comment pointedly vague. Peregrinus is a puzzle, he wrote, before asking whether the character is only a memory or is holding something back, and telling fans to watch the broadcast for the answer.
Miyuki Sakurai voices Eleonora, a knight who grew up alongside the seven brothers. She singled out the calm, fidgety air between Eleonora and Nemukunai, the brother whose defining trait is that he never gets sleepy. Natsumi Fujiwara plays Princess Brunhild of Marronnier and pointed to the small, warm exchanges between the princess and Samugariya, the brother who is always cold. Fujiwara said she was genuinely surprised to be offered the role after reading the manga.
yama Co-Wrote the Opening With Seiji Kameda
The opening theme is "Sayonara wa Iwanai" (roughly, "I Won't Say Goodbye"), performed by solo singer yama. Music producer Seiji Kameda came aboard for the track, and the two share the writing and composition credit.
yama said the series left them feeling warm after finishing it, and described the writing process with Kameda as unhurried, with the two picturing the same scene. Listening back later, yama felt the song had outgrown the role of a tie-in track and would stay with them for years. In their comment, yama framed the title as a prayer rather than a refusal: partings arrive no matter what, but the time spent together is a beautiful gift that stays in your heart.
Kameda's comment is shorter. He said he had been a fan of yama's voice for a long time, and that being asked to co-write the theme for the adaptation delighted him. Both read the manga closely and finished the song with the image of the art coming to life in mind.
The second trailer, published alongside the casting reveal in a report from Japanese entertainment news site Anime Anime, plays the song in its back half and gives each of the seven brothers a solo voice line for the first time.
Seven Brothers, Eight Kingdoms
Nao Iwamoto's manga has run in Shogakukan's josei magazine Monthly Flowers since 2016 and reached its tenth year of serialization in 2026. The Marronnier Kingdom sits at the center of eight nations, and its seven brothers, all knights, are dispatched as ambassadors to the seven surrounding countries, where each finds the person he is fated to meet. The manga topped the women's category of Takarajimasha's Kono Manga ga Sugoi! 2018, an annual Japanese critics' and booksellers' poll, and has been translated and published across Europe and Asia.
The brothers go by their traits rather than given names. Kengo Takanashi voices Nemukunai, Satoshi Inomata voices Samugariya, Akeno Watanabe plays their mother Baribara, the female general who commands the kingdom's knights, and Show Hayami handles narration.
Kiyoko Sayama (To Your Eternity, Skip Beat!) directs at J.C.Staff, with series composition and scripts by Shinzō Fujita, character designs by Yuriko Maeda, music by Yoshiaki Fujisawa and sound direction by Jin Aketagawa.
Looking Ahead
The Seven Knights of the Marronnier Kingdom starts Saturday, October 3, 2026 on NHK Educational TV, the public broadcaster's education channel, in a 6:25 p.m. to 6:50 p.m. slot. NHK ONE, the broadcaster's streaming service, is set to carry simultaneous and catch-up streams inside Japan.
International plans are less clear. Amazon Content Services appears in the anime's copyright line alongside NHK and NHK Enterprises, and English-language outlets including Anime News Network have reported a worldwide Prime Video release. The Japanese announcement itself covers only the domestic broadcast.
English readers can start on the source material now. Seven Seas Entertainment publishes the manga in English, and the Japanese edition reached its 11th volume in June 2026.