Everything can be collected, generally gold and silver coins, ancient coins, stamps, old books, autograph books, telephone cards, tickets, swords and minerals.

Advanced collection of sports cars, famous calligraphy and painting, porcelain.

Personalized collection of bottle caps, coke bottles, McDonald's toys, corpse specimens, bones and so on.

In short, you can collect anything you are interested in, and you don't have to force it.