Manga Kenkanryu is a controversial manga book that was published in Japan in 2007. It's a book all about Korean and Chinese people, and some people say it is very mean and hurtful towards those people.
The author, who is Japanese, writes in the book that he doesn't like Korean or Chinese people very much, and makes fun of them in a lot of ways. He also says some really mean things about women.
A lot of people, both in Japan and in other countries, were very upset about this book when it came out. They said that the author was being racist and that this kind of hate speech was not okay.
Many people want to ban Manga Kenkanryu so that it can't be sold or read anymore. But some people think that it is important to have free speech and that the author should be allowed to the book.
In short, the manga Kenkanryu is a very controversial book that has caused a lot of debate about freedom of speech and racism.