To provide a tag system or the like allowing flexible access restriction.

The tag system includes: tags 10-1 to 10-14 each given with a prescribed authority level; and a restriction device (a gate device 30) performing the access restriction based on the authority level given to the tag. The tag has: a communication means {an RF (Radio Frequency) transmission/reception circuit 12} performing inter-tag communication with another tag; and a giving means (a control circuit 14) for temporarily giving authority of a level different from the authority level previously given to the other tag to the other tag via a communication means. When a new authority level is given, the restriction device executes the access restriction based on the new authority level.