Description: Episode 4, the 2026 reunion and one revealing counterexample make Kurosu's choice of names fascinating. Plus the inner commentary he might be hiding.
Spoilers for the first season and episode 20, aired in October 2026.
In the Japanese spy thriller VIVANT, Shun Kurosu (Tori Matsuzaka) works with Yusuke Nogi (Masato Sakai), who also has another personality called F. An intriguing fan theory says that Kurosu addresses F as “senpai,” a respected senior, and the gentler Yusuke as “Nogi-san.” It is an interpretation, not an officially confirmed naming rule. [1]
Episode 4: Did the wrong Nogi answer?
Kurosu pretends to help Yamamoto escape, then reveals that he is part of the secret Beppan unit. He calls out “senpai.” Nogi and F struggle over who will take the lead; F eventually steps forward for the interrogation. [2][3]
Fans have focused on Kurosu's switch to “Nogi-san?” during that encounter, a detail covered by Japanese media on October 12, 2026. [1] Suppose he expected the formidable F but got a gentle reply from Yusuke. Suddenly his choice of name sounds like an identity check.
Imaginary subtitles inside Kurosu's head
This is invented inner dialogue for fun, not a scene from the show.
Kurosu: “Senpai.” Thought: (Great, time for the terrifyingly competent senior.) Nogi responds softly. Thought: (Wait. Is this the Yusuke shift? Did I dial the wrong extension?) Kurosu: “Nogi-san?” F takes over. Thought: (There he is! Yamamoto, your trouble has just clocked in.)
On the outside, Kurosu stays perfectly cool. On the inside, he might be operating a telephone switchboard for two people who share one face. The handover signal is a change in the eyes.
Reading a face isn't the same as knowing a secret
Yusuke is gentle and occasionally hesitant; F changes his gaze, voice, posture and decision-making pace. Sakai's abrupt transformation drew attention when episode 4 aired in 2023. [3] A partner like Kurosu may know these signals by heart.
But spotting a shift does not prove Kurosu understands F as a separate personality. He could simply distinguish everyday Nogi from mission-mode Nogi.
Why “senpai” in episode 20 hits differently
On October 11, 2026, the imprisoned Kurosu was reunited with Nogi's team and called him “senpai.” [4][1] If that name means F, he has recognized the senior he can rely on. If it means Nogi as a whole, it is just as moving.
There is a counterexample. Late in the first season, Kurosu believes Nogi betrayed their comrades and turns against him. When he learns that the others survived, he returns to the respectful “Nogi-san.” [5] The names may register trust and emotional distance, not only which personality is present.
Imagine his very first switch: (Same face. Different boss. Should somebody have told me?) Years later: (Ah, Yusuke. Ah, F. Oh, Yusuke again.)
And what do F and Yusuke each think of Kurosu? One face, two very different personalities, and a partner who may care about them both: that deserves its own spin-off.
References (5)
- 日刊スポーツ, 黒須の「先輩」と乃木の呼称に関する考察, 2026-10-12 nikkansports.com
- スポニチアネックス, 『VIVANT』第4話 別班の正体, 2023-08-06 sponichi.co.jp
- J-CASTニュース, 堺雅人の第4話の人格切り替え演技, 2023-08-07 j-cast.com
- TBSテレビ, 日曜劇場『VIVANT』第20話番組案内, 2026-10-11 tbs.co.jp
- ENCOUNT, 黒須が「乃木」呼びから「乃木さん」に戻る場面, 2023-09 encount.press
