Hot to increase skill max level beyond 250?

[Darkness]

The question is on the title. A lot of my skills are stuck on 250 right now, how to go further?

[Rafein]

I do know DoJo increases but, but can not remember if there was something before that.

Could check to see if it is a resource issue. Hover over upgrading a skill. If it gives a value, you need more Stone/Crystal/Leaf. If it says zero, you are at max.

[Darnavir]

Skill level cap is increased only by rank and rank cap is increased only by dojo rank.