An exorcist from the Ouma Empire. In addition to swordsmanship, this young man is also skilled at martial arts and curses (magic).
Kei's personality is rather cheerful and playful despite his serious appearance and his position as the oldest in VΔLZ. He also has a mischievous side that has most often comes out when interacting with Haru. He enjoys singing and often thinks of interesting/unique things to do, which has lead to some diverse content on his channel. With his group mates, he is playful and mischievous, however he tends to be bullied or teased by his NIJISANJI senpai.
Kei's channel was created on 27 February, 2020. He officially debuted on 2 April, 2020, starting his liver activities on Twitter. Later, he made his YouTube debut on 4 April, 2020.
On 15 May, a collab cover of Hail Holy Queen from Sister Act was released, in which he sung with Levi Elipha, Debidebi Debiru, Melissa Kinrenka, Todoroki Kyoko, Sister Cleaire, Sukoya Kana, Hayase Sou and Genzuki Tojiro, making it Kei's first cover song.
On 21 November, VΔLZ's original song, Ukiyo no Enbu (浮世の演武), was released. The song was composed by Tojiro, while all three wrote the lyrics.
On 14 December, Kei's original song, Kamisama no Negai wo Kanaeta Uta (神様の願いを叶えた歌), was released. The lyrics to the song are a Marshmallow (an anonymous messaging service) that Kei wrote to Fumi in a stream. The song was composed on a different stream together with Tojiro. Tojiro created the instrumental and mixed the song.
On 30 April, Kei revealed his 2.0 brush-up.
On 3 August, he revealed his 3.0 brush-up.
On 25 September, he debuted his first new outfit. Along with it he also got two new hairstyles, a bun to his used-to-be ponytail and short hair. In this outfit, he has a windbreaker (that can be taken off) on top of a white hoodie that bears Muu-chan's face on the hood, black ankle-cut trousers, sneakers, and a lime-green wrist watch.
On 14 November, he revealed his 3rd outfit, which was a matching school uniform outfit with VΔLZ. The three members revealed their outfits in a relay following the same order as their debut, with Tojiro going first, Kei second, and Haru third.
- From 20-21 June, he participated in the second NIJISANJI Splatoon Tournament together with Aiba Uiha, Yumeoi Kakeru, and Kuroi Shiba as team B, "AiOiKuroiNagaoKei". They ranked 3rd.
- On 28 November, he participated in the NIJISANJI Underwater Mario Kart Championship. Kei tied for 1st with Aizono Manami.
- From 19-26 December, he participated in the third NIJISANJI Mario Kart Cup. He broke through the qualifiers and quarter-finals, advancing to the semi-finals. However, during the semi-finals he placed 8th and was unable to advance to the finals.
- On 24 January, he participated in Apex Legends VTuber Most Cooperatitive Tournament S2 together with Yukishiro Mahiro and Elu as team "Apex Boxing Club". The team ranked 19th.
- On 12 June, he participated in NIJISANJI APEX Party with DETONATOR together with Gundo Mirei and TIE's PRiZE as team "Miretan, Puratan, Nagao Kei". They ranked 5th.
- On 26 June, he participated in the NIJISANJI Baby Park Cup and placed 1st.
- On 22 August, he participated in Apex Legends VTuber Most Cooperatitive Tournament S3 together with Yukishiro Mahiro and Kaminari Qpi as team "MahiMahiKyuukeiChuu" (まひまひきゅーけいちゅー！). The team ranked 15th.
- On 30 August, he participated in Battlefield V BFJ Streamer Cup as Team B's Squad Charlie along with Higuchi Kaede, Shibuya Hajime, and Kanda Shoichi.
- On 17 October, he participated in the Battlefield V BF Streamer Cup as Team A's Squad Fox with Mayuzumi Kai, Fuwa Minato, and Saegusa Akina.
- On 20 November, he participated in the third NIJISANJI Splatoon Tournament together with Yukishiro Mahiro, Elu, and Levi Elipha as team C, "1LVK". During the preliminaries, the team was able to defeat team G, but lost to team F and was unable to advance to the semi-finals.
- On 18 December 2021, he participated in the 4th NIJISANJI Mario Kart Cup's first team competition with Elu, Tsukino Mito, Hoshikawa Sara, Gwelu Os Gar, and Yorumi Rena as team F, "Team Baby Park". The team placed 2nd.
- From 19-26 December 2021, he participated in the 4th NIJISANJI Mario Kart Cup's individual competition. He made it to the finals and placed 2nd, earning himself a seeded position for next year's competition.
Mascot and Fans
- Muu-chan (むーちゃん) is a shikigami (god in the form of a small ghost) that serves as somewhat of a mascot to Kei. Muu-chan's appearance resembles a cat with white fur. It has scratches on its right cheek and is depicted holding a staff and a book. In streams, Muu-chan is represented by a portrait that Kei drew.
- Muu-chan as no specified gender or age.
- Its birthday is on June 6th.
- Apparently Muu-chan has blue eyes.
- Muu-chan can walk on both two legs and four legs. It can also levitate.
- Tojiro drew the Muu-chan badge for Kei's YouTube membership.
- Kei's fans are called "16KBG" (ケイボーイ＆ガール - Kei's boys and girls).
- His waiting room phrase is "taiki" (待機). He greets his viewers with "kon-mabushi~" (こんまぶし〜) and ends his streams with "otsu-mabushi~" (おつまぶし～).
- "VΔLZ" (pronounced ヴァルツ, like "waltz") - Kei, Genzuki Tojiro and Kaida Haru (These three are debut-mates).
- "Fukeizai" 「フ景罪」 - Kei and Fumi.
- "KeiAi" 「けいあい」 - Kei and Aiba Uiha.
- "Apex Boxing Club" 「Apexボクシング部」 - Kei, Yukishiro Mahiro, and Elu.
- "AirKei" 「エア景」 - Kei and Harusaki Air.
- "NagaoChigu" 「ながおちぐ」 - Kei and Nishizono Chigusa.
- "NIJISANJI Team Rocket" 「にじさんじロケット団」 - Kei, Fumi, and Fumino Tamaki.
- "Tamenandesu" 「タメナンデス」 - Kei and Oliver Evans.
- "Big Voice" - Kei, Yukoku Roberu, and Gil.
- Color: #625DA1 
- He shares the same character designer with Kuzuha from NIJISANJI, Chiharu from VirtuaReal and Yogiri from hololive China.
- Kei's voice has been noted to resemble fellow NIJISANJI member Ibrahim, so much so that he even had a collaboration stream with Melissa Kinrenka where he impersonated Ibrahim in an attempt to prank Furen E Lustario.
- Kei once ordered a pizza to Haru's house without permission after Haru replied to Genzuki's tweet saying he wanted to have another pizza party. As a result, the three of them gathered at Haru's house to have a pizza party and an impromptu stream where they sang and ate.
- Like his debut-mates, he likes to sing and does off-collab singing streams with VΔLZ, sometimes performing with the cajon (he's also currently learning the bass).
- Kei is well-known as a "忖度師" (sontaku master, someone who performs unspoken orders for others) by Livers and fans around, stemming mostly from his collabs with Fumi and his dedication to satisfy her mood and requests, as well as his peers. Examples are:
- Memorizing the 'Keep Talking and Nobody Explodes' manual in two days in preparation for his collab with Fumi.
- Writing a Kusomaro anonymously to Fumi because she hadn't been getting any and wanted some, only to be later caught by her. Said kusomaro later ended up being turned into his first original song.
- Learning morse code as part of his punishment from Tsukiichi. He put his morse code skills up to the test in this Fukeizai collab.
- He hit 100k subscribers in the stream where he was trying to learn morse code. The title of this stream specifically stated that he didn't want to hit 100k while learning morse code. He told his listeners to forget about it and pretend he got 100k subscribers during the NijiMen singing relay later that night as he finds it much cooler over the morse code stream.
- Kei has taken the TOEIC (Test of English for International Communication) before and scored an 850 (the average score is around 500), but said he hasn't used his skills for a while and thinks it has dropped to 600. Additionally, on the Eiken Test in Practical English Proficiency, he achieved Grade 2.
- He has also studied Portuguese before.
- Kei has an older sister, who he lives with, and a younger brother, making him a middle child. He has mentioned his sister being friendly terms with Tojiro, and that her favourite liver is Gwelu Os Gar.
- Kei occasionally shares anecdotes about conversations he has with his sister on Twitter and often mentions her on stream.
- Kei sang "A Whole New World" with his sister in this singing stream.
- Kei spent 9 hours building a literal mountain around Haru's home in Minecraft in retaliation for a prank Haru played against him, with the help of Genzuki who helped out for the first 3 hours.
- When Haru played Minecraft after the completion of the mountain, he had difficulty finding his home as the mountain blended in with the rest of the scenery. He now resides inside the mountain.
- Kei spent a total of 39 hours in 5 days challenging himself to speed run Pokemon Sapphire while memorizing a speed run guide. With the help of two skilled speedrunners coaching him and luck from Tojiro, he managed to beat his own record with the fastest time of 2h 27m 22s.
- Kei usually tweets his stream schedule for the next day the night before and then reconfirms his schedule when he wakes up.
- He is prone to oversleeping, so his noon streams are sometimes delayed by 30 minutes.
- Kei has a poor sense of direction. When he gets lost in Minecraft, he asks his viewers to help him get where he wants to go.
- Kei is a dual wielder. His katanas are named "Ouka Suijin" (桜華水刃), and are passed down in his family. They can be seen attached to his right leg by a thigh holster. After being asked about the inconvenience of this placement, he said they're attached there "because it's cool" and that he doesn't need to unsheathe his katanas because he can summon them instantly through magic, similar to how the Keyblade is summoned in Kingdom Hearts.
- He has a lot of life experience, including: swimming, tennis, band, dancing (jazz, ballet), co-ed cheerleading, being a suit actor for hero shows, riding a moped, using long spears and ninja stars, etc.
- Kei likes cats a lot, especially black cats.
- 長尾 景 / Nagao Kei【にじさんじ】 - YouTube Channel
- Kei's corporate profile on the official NIJISANJI website
- @kei_nagao2434 - Twitter Account
- kei_nagao2434 - TwitCasting Channel
- #景くんあんね - General, egosurfing
- #景成長中 - Stream talk
- #長尾百景 - Fan art
- #長尾夜百景 - Fan art (questionable)
- #長尾背景 - Thumbnails
- #景音 - Commentary on released songs
- #ながおんせい - Commentary on released voice dramas
- 長尾景 - Unofficial NIJISANJI Wiki
- 長尾景 - Nicovideo Encyclopedia
- 長尾景 - Pixiv Encyclopedia
- 长尾景 - Moegirl Encyclopedia
- Kei's corporate profile on the official NIJISANJI website. (n.d.).
- Elipha, L. [レヴィ・エリファ-Levi Elipha-]. (2020, May 15). 【合唱コラボ】Hail Holy Queen【にじさんじ/レヴィ・エリファ】 [Video File]. YouTube.
- Nagao, K.. (2020, June 2). 【歌ってみた】God knows…/涼宮ハルヒ（CV平野綾）【涼宮ハルヒの憂鬱】【長尾景cover】【にじさんじ】 [Video File]. YouTube.
- Genzuki, T. [弦月 藤士郎 / Genzuki Tojiro【にじさんじ】]. (2020, November 21). 【オリジナル曲】浮世の演舞 -Full ver.-/VΔLZ【甲斐田晴/弦月藤士郎/長尾景/にじさんじ】 [Video File]. YouTube.
- Nagao, K. [長尾 景 / Nagao Kei【にじさんじ】]. (2021, September 25). 【#長尾景断髪式】前を向いて歩こう【長尾景/にじさんじ】 [Video File]. YouTube.
- Vtuber Most Cooperatitive Tournament #2 [Web Page]. (n.d.). Liquipedia - Apex Legends.
- Vtuber Most Cooperatitive Tournament #3 [Web Page]. (n.d.). Liquipedia - Apex Legends.
- BFJ. (2021, August 30). [Battlefield Japan Community BFJ Streamer Cup] [Tweet]. Twitter.
- Based on Ichikara's .link page
- Nagao K. [長尾 景 / Nagao Kei【にじさんじ】]. (2020, April 25). Nagao Kei and Meifu Empire Impersonation Prank Stream [Video File]. YouTube.
- Nagao, K. [長尾 景 / Nagao Kei【にじさんじ】]. (2020, October 4). Kei building a mountain over Haru's house Minecraft Stream [Video File]. YouTube.