Manga series get prequels, spinoffs, and adaptations all the time. It is rarer for a manga to get a sequel, but it does happen. Prequels and side stories are the most common. However, they rarely get incorporated into their anime series. Sometimes parts of these stories may appear in an OVA or two, but that’s about it.
That’s why a lot of fans of bigger anime shows may not know that their favorite stories have spinoffs to check out. All eight of these anime have manga prequels that help shape their world’s lore. There will not be any spoilers for either the main manga/anime or the prequels, so read freely and go on to enjoy the material.
8 Attack on Titan: Before the Fall
Attack on Titan has a lot of manga spinoffs, but the most important among them is Attack on Titan: Before the Fall. It started as a light novel series in 2011 and ended in 2012. In 2013, a manga adaptation began which ended in 2019. It had a longer run than the original format.
The story is divided into two parts. One looks at the creator of the ODM gear, Angel Aaltonen. The other part looks at a boy, Kuklo, who was born from within Titan remains. These stories date back 70 years before the original begins.
7 Shonan Junai Gumi
It may surprise some fans of Great Teacher Onizuka that it is the third part in a bigger manga series. The first two parts were never adapted into full anime, although there were shorts. These earlier stories, Shonan Junai Gumi and Bad Company, take place while Onizuka is still a street punk. The first started in 1990 and ran until 1996. The other just had one volume, which was also released in 1996.
Fans of those two series should also know there are two sequels to Great Teacher Onizuka as well. GTO: 14 Days in Shonan is more like a side story, but GTO: Paradise Lost is a full-fledged sequel. That manga began in 2014 and is still ongoing.
6 Hellsing: The Dawn
Hellsing: The Dawn is a brief prequel that was never finished. It takes place during World War II and sees Alucard, as a female, partnering up with a much younger Walter to take on the Nazis. To be more precise, they are going after Millennium in their beginning phases. This is 55 years before the original story begins.
There were only six chapters made before it was abandoned. It did get a three-episode OVA as well. There is a lot of potential here if it ever gets restarted — but the possibilities of that are uncertain.
5 Jaco The Galactic Patrolman
Jaco the Galactic Patrolman is a prequel to the origins of Dragon Ball. This may be a shocker, since Dragon Ball is not in the name. It’s another short prequel too, as only one volume was published as of 2013.
This story sees the titular Jaco crash land on Earth in his pursuits to protect it. Without giving too much away, he was supposed to prevent Goku from landing there. Obviously, he fails, but that turns out to be a good thing since the series wouldn’t exist otherwise. Jaco has since appeared in Dragon Ball Super in smaller roles.
4 Magi: Adventure Of Sinbad
Magi: Adventure of Sinbad is a prequel to Magi: The Labyrinth of Magic. Sinbad is the King of Sindria in the original anime. It is assumed he had many adventures before it began since he had amassed a huge following.
Sinbad’s spinoff lasted from 2013 to 2018 compared to the original manga, which spanned from 2009 to 2017. Unfortunately, neither anime adaptation ever finished their stories, which is a shame. Sinbad got one season whereas the original got two.
3 Mobile Suit Gundam: The Origin
Mobile Suit Gundam: The Origin is a retelling of the original anime that began this giant mech series. It focuses on Char more and his side of the war. It’s like a prequel and a reboot at the same time.
It ran between 2001 and 2011 in manga form, and also got an anime adaptation in 2015. There have been sequel manga stories since then as well. Char is just a character that fans can’t get enough of, which is why these spinoffs keep happening long after the original aired in 1979.
2 My Hero Academia: Vigilantes
My Hero Academia: Vigilantes takes place years before the original story begins. It is a bit unclear on purpose, but is enjoyable all the same. It starts as a more comedic story, following some vigilantes as they try and protect their city. Their powers aren’t as spectacular as those in the main story, but eventually, they evolve and things get a bit more interesting.
There are a lot of returning characters, like Mr. Aizawa, who has a huge role and reveals a lot of important backstory about himself. The prequel began in 2016 and is still going strong.
1 Yu-Gi-Oh
When the Yu-Gi-Oh anime was brought over to the West, it skipped a lot of the early chapters of the manga. The first two arcs are completely skipped while the third was adapted but changed to be more kid-friendly. That’s when Yugi and Kaiba fight. This then leads to the fourth arc which is the Duelist Kingdom.
This example isn’t citing any spinoff manga; rather, it's meant to encourage fans to check out the manga for some missing details. The story is much darker too, perfect for older fans who loved Yu-Gi-Oh when they were younger. There was a season in Japan that covered these sections in the manga. It is commonly referred to season zero for those interesting in watching it instead.