Borderless (ボーダレス) is a crossover Sakamichi Series mystery drama. The show aired from March 7, 2021 - May 9, 2021.
- Episodes: 10
- Broadcast network: dTV
- Air time: Sunday, 23:00 - 23:45
- Opening theme: Hajimari no Period (はじまりのピリオド) (Thinking Dogs)
Nao, a high school girl living a self-proclaimed "normal" life, is one day approached by her mysterious classmate Kiri in the school library. Kiri invites Nao to come with her to visit a scene of a murder in Kiri's neighborhood which she's using as inspiration to write a novel.
Meanwhile, sisters Haru and Kei, witness their father being beaten by someone on their mountain cottage. The sister flee, only to be chased by the attacker.
Kotone, works at a coffee shop run by her father, after failing the entrance exam for music college. She works with her childhood friend Kazushi, and the atmosphere in pleasant. Her younger sister Kanon, is worried about Kotone, but spends her days devoted to her band.
A mysterious girl stands on her balcony in the rain. What is beyond the gate that looks at?
These four stories will intersect, as the boundaries between each girl gradually become borderless...
- Creator: Tetsuya Honda (Original Author)
- Director: Kanai Ko
- Music: Matsumuro Seiya
- Morita Hikaru - Mori Nao
- Saito Kyoko - Katayama Kiri
- Watanabe Risa - Yatsuji Haru
- Hamagishi Hiyori - Yatsuji Kei
- Kobayashi Yui - Ichihara Kotone
- Hayakawa Seira - Ichihara Kanon
- Endo Sakura - Matsumiya Yuuki
- Kokushou Sayuri - Matsumiya Hiroko
- Tezuka Tooru - Matsumiya Shigenobu
- Hamatsu Takayuki - Yatsuji Kozo
- Miyakawa Ichirouta - Ichihara Akira
- Konno Ayaka - Saeko
- Oshida Gaku - Nakajima Kazushi
- Chitose Ruto (Root) - Shinozaki Maya
- First collaboration Drama between Nogizaka46, Sakurazaka46, and Hinatazaka46.
- Based on novel "Borderless" by Tetsuya Honda.