no prep , standard equipment , In character , Round 1 - animated versions of both , Round 2 - comic / manga versions for both
Location - Kōryō High School
Both of them start about 25 feet from each other
You need to be more detailed on this battle. Leonardo is in multiple series and comics.
First, TMNT was animated in 1987, then 2003 (STRONGEST VERSION), and now we have this new one from 2012. You can use all of them as feats doesn't matter to me.
He's a much smarter fighter than Kenichi is. And depending on which version there is, he can take it pretty easily.
Kenichi wins both
Seikuken for the win in Round 1 Not to mention the training in several Martial Arts and Experience. The Mubyoshi is a sure kill against this Leonardo
Ryuusei Seikuken + Korui Nuki for the win in Round 2 This one is a no-brainer, Kenichi fought against tough weapon users and come up top or survived.