by Japanese singer yama will digitally release “Sayonara wa Iwanai”, the opening theme song for the upcoming TV anime The Seven Knights of the Marronnier Kingdom, on October 7, 2026.
The announcement comes just days after the anime’s television premiere on NHK E-Tele on October 3, giving fans the opportunity to hear the complete version of the opening song shortly after the series begins. The song is featured in the anime’s second promotional video, which was released alongside additional cast information in September.
Produced by acclaimed musician Seiji Kameda, “Sayonara wa Iwanai” was created through a collaboration between yama and Kameda, who jointly handled the lyrics and composition. Kameda is also responsible for the arrangement and production.
The song explores themes of love, everyday happiness, precious memories, and the sadness of an inevitable farewell. Its emotional subject matter closely matches the anime’s focus on relationships, journeys, encounters, and the bonds formed between people.
yama’s New Song Captures the Meaning of Everyday Moments
“Sayonara wa Iwanai,” which translates roughly to “I Won’t Say Goodbye,” is designed around the emotional contrast between ordinary happiness and the possibility of separation.
According to the song’s creators, the lyrics and melody portray the happiness of spending time with someone important, the small moments that make up everyday life, and the reality that even precious relationships may eventually face a farewell.
This emotional approach makes the song a natural match for The Seven Knights of the Marronnier Kingdom, a fantasy romance that combines adventure with relationships and personal growth.
Rather than focusing only on the excitement of a fantasy journey, the song appears to emphasize the emotional value of the people characters encounter along the way.
Kameda also commented that he read the original manga carefully while working on the song and imagined the artwork and characters coming to life through animation. He said the recording was created with great care and expressed his hope that “Sayonara wa Iwanai” would become an important song for listeners.
Digital Release Date and Song Credits
The full digital release of “Sayonara wa Iwanai” is scheduled for October 7, 2026.
Song Information
- Title: “Sayonara wa Iwanai”
- Artist: yama
- Lyrics: yama, Seiji Kameda
- Composition: yama, Seiji Kameda
- Arrangement: Seiji Kameda
- Production: Seiji Kameda
- Digital Release: October 7, 2026
- Role: Opening theme for The Seven Knights of the Marronnier Kingdom
The song is already being promoted through the anime’s second PV, allowing viewers to hear a preview before the full digital version becomes available.
The Cover Art Was Inspired by yama’s Beloved Dog
The digital release artwork also has a personal meaning for yama.
The cover illustration was inspired by the artist’s own memories with a beloved dog. The creative direction aims to express the warmth and tenderness of spending time with an important companion.
This personal inspiration adds another emotional layer to a song that already focuses on cherished relationships and the fear of eventual separation.
The connection between the artwork and the song’s theme also fits the broader emotional atmosphere of The Seven Knights of the Marronnier Kingdom, where relationships and encounters play an important role in the story.
What Is The Seven Knights of the Marronnier Kingdom About?
The Seven Knights of the Marronnier Kingdom is a fantasy-romance anime based on the manga by Nao Iwamoto.
The manga has been serialized in Shogakukan’s Monthly Flowers since 2016 and has reached 11 collected volumes as of September 2026. The series has also been translated and published in countries including France and Spain, giving the original manga an international audience.
The story takes place in the Marronnier Kingdom, which is located at the center of a continent made up of eight countries.
The kingdom’s female general, Baribara, has seven sons. Each brother has a completely different personality and ability.
Their unusual characteristics are reflected in their nicknames:
- Nemukunai – “Never Sleepy”
- Hakua – “Philanthropic”
- Atsugariya – “Gets Hot Easily”
- Samugariya – “Gets Cold Easily”
- Kemono Tsukai – “Animal Tamer”
- Kenji Man – “Sword Expert”
- Harapeko – “Always Hungry”
Despite their differences, the seven brothers share a common dream: to someday become knights who can save a princess in a cool way.
Their lives change when they are sent to seven different countries as ambassadors.
What begins as a diplomatic mission gradually becomes a journey filled with new encounters, challenges, romance, and questions about their own destinies.
A Fantasy Romance With Adventure and Diplomacy
Unlike a conventional fantasy story that focuses only on battles or magic, The Seven Knights of the Marronnier Kingdom places considerable emphasis on relationships, diplomacy, adventure, and romance.
The seven brothers are sent away from their homeland and must experience unfamiliar countries and cultures.
Each journey gives them an opportunity to meet new people and face situations they could not have experienced while living in the Marronnier Kingdom.
This structure also allows the anime to introduce multiple characters and locations as the story progresses.
The official description characterizes the series as a fantasy romance of love and adventure set in a medieval-style fantasy world.
For viewers who enjoy character-driven fantasy anime, the series could offer a different experience from action-heavy fantasy titles.
When Does The Seven Knights of the Marronnier Kingdom Anime Premiere?
The TV anime will officially premiere in Japan on:
Saturday, October 3, 2026, at 6:25 p.m. JST
It will air weekly on NHK E-Tele.
The series is also scheduled for streaming.
Prime Video will offer worldwide exclusive streaming beginning October 4, 2026, according to the official promotional announcement. NHK ONE is also scheduled to provide simultaneous streaming and one-week catch-up availability in Japan.
Anime Broadcast Information
- Anime: The Seven Knights of the Marronnier Kingdom
- Japanese Title: Marronnier Oukoku no Shichinin no Kishi
- Premiere: October 3, 2026
- Broadcast: NHK E-Tele
- Broadcast Time: Every Saturday at 6:25 p.m. JST
- Streaming: Prime Video worldwide
- Original Manga: Nao Iwamoto
- Animation Studio: J.C.STAFF
Streaming schedules can vary by region, so international viewers should check Prime Video in their local market for availability.
Main Cast of the Anime
The anime features seven voice actors portraying the seven knight brothers.
The main cast includes:
- Kengo Takanashi as Nemukunai
- Makoto Tanikawa as Hakua
- Haruki Ishiya as Atsugariya
- Keishi Inomata as Samugariya
- Kiyoto Mizuno as Kemono Tsukai
- Taishi Murata as Kenji Man
- Reiji Kawashima as Harapeko
Additional cast members include Miyuki Sakurai as Eleonora, Natsumi Fujiwara as Princess Brunhilde, Takeo Koyasu as Elliott, Kazuyuki Okitsu as Hugo, Akino Watanabe as Baribara, and Show Hayami as the narrator.
The large ensemble cast reflects the series’ broad fantasy world and its focus on multiple characters.
Anime Staff and Production
The anime is being produced by J.C.STAFF, a studio with extensive experience working on television anime.
The production team includes:
- Original Work: Nao Iwamoto
- Director: Seiko Sayama
- Series Composition: Shinzo Fujita
- Character Design: Yuriko Maeda
- Music: Yoshiaki Fujisawa
- Animation Production: J.C.STAFF
The official promotional material also confirms the involvement of a number of experienced staff members behind the series.
With its combination of fantasy settings, romance, diplomacy, and character relationships, the anime is positioned as one of the more distinctive fantasy-romance titles of the Fall 2026 anime season.
The Second Promotional Video Features yama’s Opening Song.
A second promotional video for the anime was released on September 7.
The PV features “Sayonara wa Iwanai” by yama, giving fans their first substantial preview of the opening theme. The same announcement also introduced additional cast members and confirmed the worldwide Prime Video distribution.
The trailer gives viewers a glimpse of the seven brothers, their personalities, the world of the Marronnier Kingdom, and the people they encounter during their journeys.
The inclusion ofYama’ss song gives the PV a strong emotional tone and helps introduce the series as more than a straightforward adventure story.
Why “Sayonara wa Iwanai” Fits the Anime
The title itself, “Sayonara wa Iwanai,” or “I Won’t Say Goodbye,” immediately suggests a story about connections and separation.
That idea is particularly relevant to the anime because the seven brothers leave their home kingdom and travel to different countries.
Their journey means leaving behind familiar surroundings while meeting new people.
As the brothers encounter new cultures, friendships, and possible romantic relationships, the meaning of saying goodbye can change from one character to another.
The song’s themes of ordinary happiness and eventual separation therefore complement the series’ central ideas.
Instead of simply emphasizing the excitement of adventure, the opening theme appears to focus on the emotional memories created during the journey.
yama and Seiji Kameda Collaborate on the Opening Theme
The song brings together two distinctive musical voices.
yama is known for an expressive vocal style that has appeared in numerous anime-related projects and Japanese music releases.
For “Sayonara wa Iwanai,” yama worked directly with Seiji Kameda, who served as producer, arranger, and co-writer.
The two collaborated on both the lyrics and composition, creating a song specifically connected to the world and emotional themes of the anime.
Kameda’s role is particularly extensive, covering the arrangement and production as well as co-writing the song.
The result is intended to work not only as an anime opening but also as a standalone song that communicates its own emotional story.
The Anime Reaches Its 10-Year Manga Milestone.
Another important point surrounding the adaptation is the timing.
Nao Iwamoto’s manga began serialization in 2016, meaning the anime adaptation arrives around the 10th anniversary of the original series’ serialization.
The manga currently has 11 collected volumes, making the 2026 anime an important new stage for a series that has spent a decade building its audience.
The story’s international reach has also expanded through translated editions, including publications in France and Spain.
The television anime therefore gives longtime manga readers a new way to experience the characters while also introducing the world to viewers who may be discovering the story for the first time.
What Can Fans Expect From the Anime?
At its core, The Seven Knights of the Marronnier Kingdom combines several elements:
- Fantasy adventure
- Romance
- Family relationships
- Diplomacy
- Character development
- Medieval-style world-building
- Seven brothers with contrasting personalities
- Encounters across different kingdoms
The seven brothers are not identical heroes. Their different personalities are an important part of the story.
Because each brother is sent to a different country, viewers can also expect the series to explore different relationships and situations rather than following only one central character.
This gives the anime an ensemble structure while keeping the seven brothers connected through their shared background.
Fall 2026 Anime Season Gets Another Major Fantasy Romance
The Fall 2026 anime season is filled with series from a wide variety of genres, and The Seven Knights of the Marronnier Kingdom adds a fantasy-romance story with a strong family and adventure component.
The anime’s Saturday evening broadcast slot on NHK E-Tele also makes it somewhat different from many late-night seasonal anime.
For viewers unfamiliar with the original manga, the anime offers an accessible starting point.
For existing fans, meanwhile, the adaptation provides an opportunity to see Iwamoto’s characters and world brought to life through animation, voice acting, music, and visual storytelling.
The opening theme will be an important part of that experience.
“Sayonara wa Iwanai” Release Information
yama’s “Sayonara wa Iwanai” will officially become available digitally on October 7, 2026.
The release follows the anime’s October 3 television premiere, meaning viewers will first encounter the song as the series’ opening theme before being able to stream the full track several days later.
Release Details
Title: “Sayonara wa Iwanai”
Artist: yama
Release Type: Digital single
Release Date: October 7, 2026
Anime: The Seven Knights of the Marronnier Kingdom
Theme: Opening theme
Lyrics & Composition: yama / Seiji Kameda
Arrangement & Production: Seiji Kameda
The digital release of yama’s “Sayonara wa Iwanai” adds another major piece to the promotion surrounding The Seven Knights of the Marronnier Kingdom.
The song’s themes of love, everyday happiness, treasured memories, and eventual separation complement an anime built around seven brothers leaving their homeland and embarking on journeys across different kingdoms.
With J.C.STAFF handling animation production, an experienced creative team, a large voice cast, and a story that combines fantasy, romance, adventure, and diplomacy, the series is shaping up to be an interesting addition to the Fall 2026 anime season.
The anime will premiere on NHK E-Tele on October 3, 2026, while Prime Video will provide worldwide exclusive streaming from October 4. The opening theme will then receive its full digital release on October 7.
For fans of yama, the release offers a new original song created specifically for an anime project. For manga readers, it marks the animated debut of a story that has been running since 2016. And for newcomers, it provides an opportunity to discover a fantasy romance centered not on a single hero, but on seven very different brothers whose journeys will take them far from home.
As the seven knights begin their journeys, “Sayonara wa Iwanai” is set to provide the musical introduction to their adventures—and to the relationships that may change their lives along the way.
