世話

Etymology
Believed to derive from. The kanji are ateji.

Noun

 * 1) care, looking after, help, favor

Usage notes
Takes the formal prefix when talking to someone outside the group (which could be anyone else when the “group” is just oneself) about a favor done for someone inside the group.

Idioms

 * : to take care of, to do a favor
 * : to receive a favor, to be obliged or indebted to someone
 * : Greeting between established business partners.
 * / : "none of your business"
 * : Greeting between established business partners.
 * / : "none of your business"

Noun

 * 1) worry