"You're worrying too much, Ryu-sei-san! Thinking too much isn't really good for you, do you know that?"

Obviously he didn't, and JK was just the type of kind, helpful person to tell him that.

JK stretched his arms up, then rubbed his belly. He was full, and he'd offered his help to someone in need - his quota for being in school had been reached, so it's time to go home. Well, not home home but somewhere far away from here.

"Well, I have to go. See you next time, ne?" Without waiting to hear the answer, JK picked up his things and headed for the door.

...without asking about the payment for his 'help'.

Just the way he intended it.