Most Fruitful Yuki is a Japanese manga series. Originally, it was a one-shot comic, but following its use as a prop in the American movie Juno, it has since been translated into many languages (including English) and has gained a cult following.
Yuki, a newly married young woman, discovers that she is pregnant and is eager to tell her husband, Kenji, a promising student at an elite ninja school. But before she gets the chance, Kenji, most of the other students, and nearly all of the teachers from his school are kidnapped by the evil wizard Gorou. Gorou is not strong enough to kill them, so he traps them. But the wise sorcerer Daichi, one of the teachers who escapes capture, discovers a magical loophole: Yuki has a chance free them...as long as she is pregnant with Kenji's child. Unfortunately, the training Yuki will need to undergo in order to successfully free her husband will likely take years, and as soon as she gives birth, the loophole disappears. She persuades Daichi to cast a spell that will keep her pregnant until she is able to rescue her husband. In addition to the minions of Gorou who she is forced to battle regularly, she also finds herself fighting scores of demons and lesser villains who have decided to take advantage of the missing ninjas. She is joined in her fight by the students and teachers who evaded capture and they will not rest until they have rescued the other ninjas.
In 2001, 17-year-old Japanese artist Hayato Saito sketched an image of a pregnant superhero, inspired by his pregnant sister, Yuki Takahashi. At the time, Takahashi was on bed rest and confided to her younger brother that she was "bored, frustrated, and scared". Saito presented the sketch to her on his next visit and began entertaining his sister with stories of a fierce warrior intent on protecting her husband and her unborn child. Over the next few months, the character and the primary storyline of the officially named "Most Fruitful Yuki" solidified. By the time Takahashi gave birth (to a healthy daughter named Hana), Saito had drawn up the whole comic and gave it as a baby gift.
In late 2002, a guest to the Takahashi house saw the book, and pitched it to the publishing house where he worked. While there were some revisions, the publishers decided to leave the story essentially intact and Most Fruitful Yuki #1 was published with a small print run in August, 2003. Based on initial sales projections, they briefly considered turning it into a series. By this time, however, Saito was beginning his second year in art school and had moved on to other projects. He was further disinclined to change his life given the compensaton they were willing to offer for him to personally work on it, nor was he willing to sell the rights to allow someone else to write his story. As Saito explained in a 2010 interview, "Even today, Yuki is still very much based on my sister in appearance and personality...if my sister were a magically pregnant ninja who's true love had been kidnapped. I could not permit someone else to write the story and possibly cause the character to do something that would bring dishonor to my sister."
Additionally, from the publishers' perspective, the sales were only moderately successful. They made money, but not enough that they were persuaded that there was a real market for pregnant ninjas: they believed that many of the sales came out of the sheer novelty of the premise. And they did not sell out of their initial print run until mid-2004. Normally, that simply would have been it. However, a number of their other manga series had extremely disappointing 2003-2004 sales; they even lost money on several of them. In contrast, Most Fruitful Yuki had not sold quickly but it had sold steadily and they had made money. Then, when several actresses from Japanese action movies announced that they were pregnant, the publishers saw a chance to make money off of their pregnant ninja.
They decided to do a reprinting. This time, they sold out more quickly. Sales continued, steadily growing over the next few years and by 2006, the comic had gained enough of a cult following to require several reprintings, each larger than the last. They began getting some overseas interest and were even planning a small English reprinting, beginning working on a translation.
Meanwhile, Juno began filming in early 2007. Writer Diablo Cody included a scene where two characters (the pregnant Juno and Mark, the prospective adoptive father) look at a picture of a pregnant rock star. Production designer Steve Saklad had created that image, but was dissatisfied with it. In an interview, he said, "It looked like a pregnant woman holding a microphone. It was okay, but it wasn't exciting, didn't fit the mood of the movie, didn't seem like something that would excite Juno. And then a friend who was very into manga and anime told me about Most Fruitful Yuki. Of course, it wasn't called that yet, it was still exclusively available in Japanese and had a Japanese title. But I thought, 'Okay, I'll take a look at it.' And I was absolutely blown away, I thought it was perfect. Fortunately [director] Jason [Reitman] and [writer] Diablo [Cody] agreed with me, so we got our guys to immediately start seeing if we could get the rights to use it."
Of course, Juno did get the rights to use the newly translated cover of Most Fruitful Yuki. And as Juno soared in popularity, so did Most Fruitful Yuki.
By this time, Hayato Saito was out of art school and eager to return to his manga roots. In his 2010 interview, he explained, "I had learned a lot in school and was most grateful for my teachers, who taught me many other kinds of art. But I found out that what I really wanted was to do manga. I wanted to use my new skills to make the best manga I could. But I thought that I would have to work on someone elses ideas, drawing the pictures that they told me to. To find out that, if I wanted to, I could draw more of my stories with the character I created and that other people would be drawing what I told them to--I was very honored." Due to Saito's inexperience, Most Fruitful Yuki was initially scheduled to be published only a few times a year, but he quickly proved himself and by February 2008 it became a monthly.
Today, Most Fruitful Yuki's sales are not that of more mainstream titles', but it has a solid following that continues to grow. It has won a number of awards in Japan, Europe and America. Yuki herself has become a moderately popular costume choice at comic book conventions--and an extremely popular choice among pregnant convention attendees.