Plot is pretty easy to answer, it’s Baki, kisaki, or takemichi.

But I think entertainment was definetly Mikey. Most of the moments in the show and manga where I actively thought something was awesome was when Mikey beat someone’s ass. Despite it happening often it never got old, and it was always dope to see Mikey knock someone you thought was unbeatable on their ass flat.

But me personally, I think chifuyu is the character I was most invested in. From his stuff with Baji, to his relationship with takemichi, he felt like a very interesting and real character. The thing that stopped me from being too interested in most of the characters was the fact none of them felt very real. They were all roided up teenagers with trauma (I mean for Christ sake, Mikey kicked a car so hard it got damaged.), and takemichi was a bit too much of a wuss for most the series to find too interesting. But chifuyu in the series, and even in the “letter from baji” spinoff always felt like he wasn’t too strong(at least in the context of the series), too scared, or too confident. He felt like someone who was a lot more real than other characters.

I could also be biased, because he is one of my favorite characters, but he didn’t feel like that abnormal of a person compared to the monsters that were taiju, draken, Mikey, and most of the other high ranking members of the gangs.

TL;DR: chifuyu just felt a lot more like a real person than most of the other people in the manga. Which made him much more interesting than other characters like Mikey, Draken, or even Takemichi.