Hey! Say! JUMP member and solo artist Ryosuke Yamada will be the lead in the upcoming Yomiuri TV and Nippon TV drama “Ichijigen no Sashiki” (一次元の挿し木 / いちじげんのさしき), which will begin airing in July every Sunday from 10:30 p.m. to 11:25 p.m. (JST).
The series is based on the popular original novel by Ryunosuke Matsushita (titled “Labyrinth of Hydrangeas and the Minotaur” in English), which has over 650,000 copies in circulation. Alongside the announcement, a teaser visual of Ryosuke as the protagonist, Haruka Nanase, featuring a variety of flowers was released.
Haruka, a graduate student researching genetics, cannot forget about his stepsister Shiharu, who disappeared during a torrential rainstorm four years ago, and believes is still alive. One day, while conducting a DNA analysis on ancient human remains, he makes a shocking discovery that hints to a major conspiracy.
Beyond layers of shifting truths lies an unimaginable conclusion. The story is a human mystery drama that challenges mysteries transcending time.
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Ryosuke Yamada
Q: What was your honest reaction when you received the offer?
A: “After receiving the offer, I read the novel and felt it was truly a mystery where you absolutely cannot predict what will happen next. I turned 33 this year, and while reading it I found myself wondering: ‘What kind of Haruka Nanase would Ryosuke Yamada become after meeting so many people, absorbing so many experiences, and expressing them throughout his life?’ That curiosity about exploring myself made me decide to accept the role.
Each character acts according to their own motives, and the drama is filled with people who each embody different forms of love. I think there are aspects of that you can only understand after gaining various life experiences, so I’m glad I can take on this role at this age and with the experiences I’ve had.”
Q: What did you think after reading the script? A: “It’s fascinating! Of course, novels have their own strengths and dramas have theirs, but the original elements added for the drama are entertaining in a different way from the novel, so I hope people enjoy them.
I think viewers will try to theorize about the story… but honestly, I don’t think they’ll be able to figure it all out! I don’t think it’s predictable, but I hope people have fun discussing their theories.
We haven’t started filming yet, but I already have the outline for the entire script. The story itself jumps back and forth through time quite a lot, and filming will probably be similar—like shooting episode 1 and then episode 7—so it’ll literally be ‘time-transcending’ filming (laughs). It’s difficult as an actor, but very rewarding. I think I’ll be spending many days staring at the script.”
Q: Tell us about your character, Haruka Nanase. Are there any similarities between him and yourself? A: “He’s a graduate student researching genetics. During his research, he analyzes 200-year-old human remains discovered in the Himalayas, only to find that the DNA perfectly matches that of his stepsister, who disappeared four years earlier. He then sets out to uncover the truth behind this impossible mystery, facing various problems and incidents along the way and becoming entangled in even greater mysteries.
To be honest… I still don’t fully understand Haruka! (laughs)
If I had to name a similarity, it would be that once he believes in something, he pursues it single-mindedly and moves straight ahead. I’m that kind of person too, so maybe that’s where we’re alike.
I think many viewers will experience the story through Haruka’s perspective, so I’d be happy if they could enjoy solving the mystery together with him.”
Q: What should viewers pay special attention to in this work?
A: “Who is an ally and who is an enemy? Who will betray whom? I think it’ll be fun to watch while constantly thinking about those questions.”
Q: The title “Ichijigen no Sashiki” inspired visuals filled with flowers and plants. Do you have a favorite flower or plant? A: “I like bonsai and actually grow them myself. One of the bonsai I grow is called shinpakku (Japanese juniper). It’s considered a bonsai themed around ‘life and death,’ where living wood and already-dead wood are fused together, and nutrients from the living part continue flowing into the dead part. Together, they form a single tree, and I feel that connects strongly with this work.
Bonsai often carry meanings. For example, goyomatsu (Japanese white pine) is considered lucky to display at the entrance because it symbolizes ‘waiting for honored guests.’ I’m drawn to that symbolism. They have deep backgrounds and histories, and some are much smaller than me yet older than I am and have lived far longer. It’s profound and fascinating.”
Q: You recently turned 33. Do you have any goals or aspirations for this year?
A: “This drama is beginning just as I’ve turned 33, and I’ll also have my first solo dome tour in June and July, so I think it’s a great start. I want to keep moving forward without losing this momentum.”
Q: What are you looking forward to during filming, and what do you want to keep in mind?
A: “I’m looking forward to spending time talking with the cast on set. Although this isn’t exactly a light mystery drama, I don’t think the atmosphere on set has to become gloomy just because the story is dark.
There will definitely be suspenseful developments, but I don’t want people thinking it’s just a depressing drama! (laughs) I hope everyone—including the staff—can enjoy filming together in a warm and friendly atmosphere.”
Q: Finally, please share a message for viewers looking forward to the drama.
A: “Since this is a human mystery drama and my character gets swept into various incidents, I want to approach filming naturally and act as though these events are really happening in the moment.
I hope viewers will follow the drama from Haruka’s perspective and uncover the truth together with him!”
Original Author Ryunosuke Matsushita
“I’m Ryunosuke Matsushita, the original author. First of all, I would like to sincerely thank everyone involved in adapting this work into a drama, as well as Ryosuke Yamada-san and all the cast members.
As I write this comment, I’ve been reflecting on many things. ‘Ichijigen no Sashiki’ is my debut work. While writing it, I never told anyone I was writing a novel, so until I submitted it for the ‘Kono Mystery ga Sugoi!’ Award on May 31, 2024, I was the only person who knew this world and its characters.
After winning the award, whenever editors mentioned names like Haruka, Shiharu, Yui, or Ushio, it felt strangely ticklish, as though someone were directly touching my brain.
Since then, many readers have resonated with the world and characters, and I’m deeply grateful for that. At the same time, I sometimes felt lonely, as though I had introduced friends known only to me to the world, and even guilty, as though I had sold pieces of my own soul.
I received the offer for the drama adaptation while I was still searching for how to deal with those changes myself.
Although I was bewildered by how quickly the roots of ‘Ichijigen no Sashiki’ spread across dimensions beyond my own understanding, meeting the production team and seeing how sincerely and passionately they engaged with the work gradually made me realize that this story no longer belongs only to me.
Recently, I’ve started to think that perhaps being a professional writer means respecting the unique version of ‘Ichijigen no Sashiki’ that forms in the minds of everyone who reads or watches it. I’m still not sure I’m fully prepared for that, though.
As both the original author and a viewer, I’m looking forward to the drama adaptation of ‘Ichijigen no Sashiki.’ Thank you for your support.”
Takashi Nakayama (Yomiuri TV Producer)
“Can genes really never lie? Can humans resist their genes?
This precious original work entrusted to us by Matsushita-sensei is an exceptional mystery. I hope everyone enjoys unraveling this grand mystery spanning 200 years.
I want viewers to see Haruka—the protagonist of this story—as soon as possible: his appearance, demeanor, and actions.
As for Ryosuke Yamada, who will portray Haruka: after meeting him, I can only say, in a cliché way, that I completely fell in love with him as a person. I became captivated. It felt as though I were being drawn in. He’s that magnetic.
And that feeling grows stronger each day.
He’s a rare person who radiates dazzling brilliance, but this time, he’ll hide that light within himself and transform it into a seductive shadow.
He’s dangerous, fragile, fleeting—so delicate that it feels as though he could break if no one supports him. Yet within his heart and body lies a desire ‘to believe’ stronger and firmer than anyone else’s.
His life is like walking on thin ice, wrapped in darkness where the truth is unclear.
I hope viewers will witness how one person struggles against and overcomes such a fate.
This is not just another theory-driven drama. Nor is it a difficult sci-fi series. It’s a human drama close to all of us—a drama about humanity itself.
I hope viewers will look not only at what is visible above ground, but also at the roots of the ‘grafting’ beneath the surface.
The cast and staff will give everything they have. We hope that on these exciting Sunday nights of a hot summer, beautiful flowers of emotion bloom in everyone’s hearts.”
Yuma Abe (Yomiuri TV Producer)
“The DNA of 200-year-old human remains excavated in the Himalayas perfectly matches that of the younger sister who disappeared four years ago.
When I read the original novel, I was instantly drawn into this ‘impossible mystery.’
Why did the DNA match? Who exactly was the sister?
New mysteries kept appearing one after another, and I couldn’t stop turning the pages.
As the story progresses, the truth repeatedly shifts, raising questions not only about human emotions but about existence itself. Yet at the foundation of the story lies something deeply universal and heartfelt: the grief of losing someone important, and the desire to keep believing in someone despite that loss.
I was profoundly moved by its depth as a human drama that goes beyond being just a mystery.
It’s a tremendous honor to adapt Ryunosuke Matsushita-san’s precious work into a serialized drama. In adapting it, we want to carefully preserve the feelings he poured into the story.
When we met Matsushita-sensei, he told us: ‘Please make this the best entertainment work possible.’
Keeping those words close to our hearts, the cast and staff are united in sincerely giving this project everything we have.
I hope viewers will stay with us until the very end to discover the truth waiting beyond this ‘impossible mystery.’
Please look forward to ‘Ichijigen no Sashiki.'”