"Kenji Hatanaka is a core character in the Japanese manga ""Nine,"" written and illustrated by Mitsuru Adachi. Kenji is a teenage delinquent and the childhood friend of the protagonist, Katsuya Niimi.

Kenji Hatanaka is introduced in the first few pages of the manga as a rough and tough high school student who has been expelled from several schools for his bad behavior. He is known to be deeply passionate about baseball, and his love for the sport becomes evident soon after he meets Katsuya.

As the story progresses, Kenji's character is revealed to be much more complex than initially perceived. He is shown to be a loyal friend to Katsuya despite their differences in personality and conflicts. Kenji also has a soft spot for his sister, who he is fiercely protective of.

Throughout the manga, Kenji's character develops as he begins to accept responsibilities and matures emotionally. He works hard to become a better person and overcome his delinquent behaviour. His love for baseball is also a driving force for him to pursue his dreams and goals.

Kenji's role in the manga is significant as he represents the struggle of adolescence and self-discovery. His character's journey is relatable to many young readers and is one of the reasons why ""Nine"" is such a popular manga.

In conclusion, Kenji Hatanaka is an essential character in ""Nine"" who represents the complexities and struggles of growing up. His love for baseball, loyalty to his friends and family, and self-discovery make his character relatable and captivating for readers."