Manga

A lot of franchises start as manga as that is cheaper to design and publish. If successful they are turned into anime and then games and other paraphenalia.

Some good manga to look at include:

• See my blog entry on Hokusai X Manga for historic examples
• The Walking Man https://www.amazon.ca/Walking-Man-Jiro-Taniguchi/dp/1908007427/
• What a Wonderful World! https://www.amazon.ca/What-Wonderful-World-Vol-1/dp/1421532212/
• Showa: A History of Japan https://en.wikipedia.org/wiki/Showa:_A_History_of_Japan
• Doraemon: https://www.amazon.ca/Doraemon-Vol-1-FUJIKO-F-FUJIO-ebook/dp/B00GTG4776/
• Akira
• Ghost in the Shell
• Astro boy and other works by Osamu Tezuka https://en.wikipedia.org/wiki/Osamu_Tezuka
• Tekkon Kinkreet

Googling will give you much better lists. This is off the top of my head.