engineering

Kizuna AI

Kizuna AI is a engineering topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Kizuna AI rather than just read about it. In short: Kizuna AI (Japanese: キズナアイ, Hepburn: Kizuna Ai) is a Japanese virtual YouTuber (VTuber) and fictional character currently part of Kizuna AI Inc., a subsidiary of digital entertainment company Activ8. From her debut in 2016 until 2021, she was the most subscribed VTuber on YouTube, with more than 4 million subscribers across three YouTube channels and 1 million subscribers on the Chinese video platform Bilibili.

Key takeaways

Kizuna AI belongs to engineering; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Kizuna AI to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Kizuna AI from memory before moving on to harder problems.

Reference excerpt

Kizuna AI (Japanese: キズナアイ, Hepburn: Kizuna Ai) is a Japanese virtual YouTuber (VTuber) and fictional character currently part of Kizuna AI Inc., a subsidiary of digital entertainment company Activ8. From her debut in 2016 until 2021, she was the most subscribed VTuber on YouTube, with more than 4 million subscribers across three YouTube channels and 1 million subscribers on the Chinese video platform Bilibili. Kizuna AI posted her first YouTube video on her "A.I.Channel" on 29 November 2016. A second channel, "A.I.Games", was opened in March 2017 for gaming content, and a third, "A.I.Channel China", opened in June 2019 for a Chinese audience. Although the first channel to use a Computer Generated (CG) avatar for vlogging purposes on YouTube was the channel of English-Japanese Ami Yamato, who debuted her first video in 2011, Kizuna was the world's first modern virtual YouTuber with characteristics typically ascribed to them, much like the one who coined the term Virtual YouTuber. Kizuna's video content is similar to many other YouTubers, consisting primarily of discussions, Q&A videos, and more traditional "Let's Play" videos, although in years later, she also began to livestream at least one time per week. Because Kizuna primarily communicates in Japanese, fans contributed translations for her videos, and there were entire unofficial communities built around these translators, filling the void of an official English community until 2020 when official subtitles started. Kizuna has performed at various anime conventions, at virtual concerts, and has also worked with many game companies. She has also appeared on television shows and has starred in commercials not limiting herself to YouTube, to the point of appearing in mid-Shibuya. She has become a popular virtual celebrity worldwide. Starting in 2016, Kizuna AI was originally managed directly by Activ8, the company that created her, under the name Project A.I. In 2018, the project was moved to in-house agency upd8. Following an announcement on 24 April 2020, Activ8 announced that Kizuna AI was moved from upd8 to a new subsidiary company dedicated exclusively to her, called Kizuna AI Inc. With the announcement, Japanese voice actress Nozomi Kasuga (春日望) also disclosed her role as the voice model of Kizuna AI and advisor of the new company. Kizuna AI Inc. formally started activities on 11 May 2020, with Eriko Matsumoto (松本恵利子) as the CEO.

Production Kizuna is an online virtual character completely constructed using software. As the identities of producers in the background are not revealed, video animators, producers, video editors, and players of games are unknown. Kizuna's YouTube channels are thought to be managed by an entire production crew, and the choice to remain anonymous comes from the wish to keep the concept of a virtual idol intact. This has caused speculation regarding the operation crew and technology. Kizuna's videos are produced by Tokyo-based digital production company Activ8. All crew members known so far to be involved in Kizuna's design are already well known. These include En Morikura in character design, Tomitake in 3D modelling, and Tda in modelling supervision. Morikura is an artist well known for illustration. Tomitake has designed many 3D models, and works alongside Tda, an expert in the MikuMikuDance 3D modelling field. The identity of Kizuna AI's voice model had long been unknown; however, on 24 April 2020 it was announced on Twitter that voice actress Nozomi Kasuga provides her voice.

Design and personality Kizuna is aware that she is a virtual character, and claims that she is an independent artificial intelligence (hence the "AI" in her name). An October 2018 article from BBC Capital noted a Mattel advertisement campaign for Barbie in 2015 with the same concept. In her first video, Kizuna introduces herself. Apart from the general meaning of "artificial intelligence", "AI" is also a pun on the kanji "愛", meaning "love" while "Kizuna" (絆) means to bond, bind and/or connect. Kizuna is designed as a young and beautiful 2.5D animated girl with moe elements, which attracts many YouTube users. Kizuna's appearance age is roughly sixteen years old, though she revealed that she is only five, with her birthday on 30 June. She has a height of 156 cm (5 ft 1 in), a weight of roughly 46 kg (101 lb), and her three measurements are 85-59-83 (34–24–33). Kizuna's overall appearance uses a pink and white color palette. She has long flowing hair, coupled with a futuristic gradient hair dye of pink. She wears a pink wobbly hairband with a butterfly knot. The hairband has a double-leaf heart-shaped design, corresponding to the word "Ai", meaning "love", in her name, and Kizuna's sleeveless white top brings about a futuristic aesthetic. It is designed to put emphasis on her back and body, as well as to make her appear slimmer. Embroidered above her chest is the letter "A". Her arm sleeves and thigh highs are decorated with lace, while her thigh highs and shorts form a zettai ryoiki area in her design. Kizuna is a passionate fan of Love Live! and Love Live! School Idol Festival; her favourite character is Nico Yazawa. During an interview with Panora, Kizuna mentioned that she pays close attention to idol groups such as Keyakizaka46 and Nogizaka46. Kizuna likes how idols follow their dreams just like herself. In her character design, she also likes to spend time in virtual space playing video games.

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with Kizuna AI

Start with the simplest possible case. Write down what Kizuna AI claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In engineering, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Kizuna AI before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Kizuna AI ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Kizuna AI

In research: Kizuna AI appears in engineering research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Kizuna AI in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Kizuna AI is common in secondary-school and first-year university syllabi. It links to neighbouring topics 21st-century Japanese actresses, 21st-century Japanese women singers, Animated characters introduced in 2016, so understanding it makes those chapters shorter.
In everyday life: Look for Kizuna AI outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Kizuna AI in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Kizuna AI means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Kizuna AI out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Kizuna AI in simple terms?

Why does Kizuna AI matter?

Because it connects several engineering ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Kizuna AI?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Kizuna AI.