On top of having a main page that lists all of Kiryu's Stats, there are also three additional tabs found here named Battle Skills, Heat Actions and Other Skills. With the help of these three sections, you can actually unlock brand new Combat Skills for Kiryu to perform when in battle. As the names of these sections might imply, each of these different forms of skills will help Kiryu in a separate area of his abilities.
Within Battle Skills, you will have the option of increasing Kiryu's core combat skills, ones such as the rate Kiryu can land consecutively hits on his opponents or even the rate at which Kiryu can dodge attacks. Within Heat Actions, you will be able to learn exactly what it will take to execute given abilities and moves while Kiryu is in Extreme Heat Mode during combat. And finally, within Other Skills, you will have the chance boost and unlock certain other various skills of Kiryu's. (There will also be an Equipment Tab where you can actually equip Kiryu with the equipment you have obtained throughout the Main Story.)