The Philosophy Behind the Latest Osamu Tezuka x AI Project

No other choices but Tezuka

This story starts with idea of a semiconductor and storage product manufacturer, Kioxia. The company's mission statement declares that they want to make the world more interesting via memory. "When we thought about doing a manga with AI, we unanimously decided that it had to be Osamu Tezuka", said Ryohei Orihara, Senior Fellow of Digital Process Innovation Center of Kioxia. "In fact, many of us read Astro Boy [Kobunsha, 1952] and were inspired to be engineers. I couldn't think of anyone other than him".

Led by curiosity and respect

The key figure was Makoto Tezuka, the eldest son of Osamu Tezuka, and the head of Tezuka Productions. When the project was proposed by Kioxia to Makoto, he saw the fact that it might not succeed as a reason to get involved, rather than a reason not to. "I think of a manga as a pure expression of human imagination, and therefore difficult to re-create with AI technology alone, particularly not in a short period of time. But at the same time, my curiosity about the unknown aspects of the project and the great respect that the engineers had for my father convinced me to participate".

Blend human hands and AI

About a month before the official kick-off of the project, they discussed and decided that it would be technically impossible to make a manga using AI alone, without human hands. The goal of the project was therefore shifted so that AI would be used as “a tool to augment human creativity.” Provisionally, they divided the work so that the character design and the plot were made by AI, and human’s ability was used to compose the frames and assess the output. Progress would be reviewed as the project went on, and, given the novelty of what they were trying to achieve, the plan would remain loose and flexible.

Unexpected wall to face

Orihara ruefully smiled when remembering the process of having the AI make characters. "I was optimistic at first", he recalled, as they collected and input facial images drawn from Tezuka's works mainly in the 1970s, but the initial results that came back were disappointing, with the AI images that bore no resemblence to faces at all. In response, he made use of various methods to supplement the amount of data, but even with 20,000 input images, the faces being output from the AI were not stable. "It turned out that Tezuka's work had a lot of exaggerations in facial expressions of the characters, and the AI could not recognize all of this. It would have been easier if it had been a graphic or realistic style manga, but we couldn't have guessed that we would have this problem until we actually tried it".

Makoto’s word as a turning point

The inability to create convincing character designs was an early stumbling block. To get around it, Kioxia proposed 'transfer' learning, using real human faces alongside Tezuka's original images. Some of the AI team, including Professor Kurihara of Keio University, initially disagreed. "We wanted to do this project to push forward technology with a spirit of research. Doesn't this become meaningless if we use means that don't align with the true purpose?", he argued. Then, Makoto helped to win Kurihara around, telling that “Osamu Tezuka himself used to practice his skills by copying actual human faces.”

Characters- more than just picture

Another concern was that the character images being created, while potentially usable, were failing to express the characters' themes. "Characters are not just pictures. Every one of them has a background, and an idea behind him or her, and the images have to express these themes. None of my father's characters were simple caricatures, and the more important they were, the more involved they were. For example, Black Jack has half-white hair, and a face that unnerves people. That's why character creation is a bedrock of the work, that becomes at the beginning of everything".

"In a computer game, you can express a character's strength using numbers as level. But that's too simple for a manga. Strength is not only physical, but also mental, and varies with time and situation, or who the character is interacting with. That's why the background of the character is important. Although it's not expressed in the story, we have developed a long-term background to Phaedo, the main character of this manga project, showing who his father is and what kind of childhood he had. The background we have made for this character is very detailed, and although it doesn't appear in the comic at all, it makes his words and actions more convincing and gives them greater depth."

Creator’s eye for plot making

The process by which the AI was trained was elaborate. The team started by taking 160 one-off works, transcribing the plots into words. This was fed to the AI, which divided the storylines into 13 distinct units, and then created new plots based upon them. From these, 10 plots were finally given to Makoto. He read through and analysed them while impressing the engineers by classifying the plots himself, declaring some to be good for one-off stories and some to be better for serials.

Seeking originality, not perfection

The final plot was lined with seemingly mysterious words: "actors, Greece, a world of action with dark and bright spaces between reality and fictional ...". "Actually, most of the plots that the engineers were confident about didn't resonate with Makoto," says Orihara. "We, engineers, were seeking perfection, but it was still eye-opening to know the attitude the creators took. Makoto truly cared about discovering something new, something that he hasn't already seen or thought about. All he wanted as a creator was inspiration. This might have been the single most important thing I learned over the whole project".

Experience makes “next”

As the work went on, the developing chemistry between the creators and the AI became a valuable asset and then, later, a source of pleasant recollections of Kioxia. "The real treasure here is the results of the trial and error process", Orihara said. "Failure is as valuable as success as important data for us. Just as many engineers and robotics researchers read Astro Boy and aspired to that path, it would be amazing if the next generation will read “Phaedo” and become inspired to become AI researchers. What if we inspired a future leader in this area? That would be an unexpected joy for us".

The only thing you can’t give up

For great manga artists, co-writing with an AI could be a potential cause of controversy and criticism. Makoto sees things more optimistically. "What was the most important thing for my father, at the core of all his works? It's a universal message about the preciousness of life. In one sense, drawing digitally or using AI might be seen as superficial. Also, and it's not well known, my father was criticized for almost every single one of his new works in his lifetime. He overlooked the criticism, though. What if my father was alive? Because he was a very curious person, I'm sure he would have been amused, and have wanted to go ahead with this project".

Reasons of positive reception

Despite the inherent controversies of re-creating a work by a late manga artist with many devoted fans, "Phaedo" has been received well. One reason for this is the transparency with which the team approached the project - they described the process and the difficulties they faced both on the web and in the related book, acknowledging the imperfections of the current AI technology and the compromises made. Secondly, Makoto Tezuka - both a creator himself, and the son of Osamu - took charge of the creative side, building trust with fans. Thirdly, the respect that all involved had for Tezuka shines through.

Whenever the history of Japanese manga comes up, Osamu Tezuka - the so-called "god of manga" - can invariably be the first name mentioned. Even in the seemingly unrelated field of AI technology, we see the influence and inspiration he has had, and even more than 30 years after his death, his futuristic yet charmingly humanistic outlook continues to have an effect on us.