This brings back strong memories from college. Everyone had black Northface zip-up jackets, so when you would go to a frat party, there would be a giant pile of jackets laid on the couches in the common room. At the end of the night, it was a crapshoot whether drunken party-goers actually found their jacket, or one of the dozens of identical ones.

The next afternoon, there would inevitably be a cascade of campus-wide emails asking for the return of jackets containing wallets/ids/keys.

The thrift shops did a strong business in supplying the most garish and distinctive "frackets" to combat this problem.

The hack here is to put distinctive stickers or something on them so anyone picking it up knows it's definitely not theirs. I've had the same umbrella in Japan for 4 years.

I really can't believe you've had a Konbini store umbrella for 4 years. They're really not that well made?

Yeah it's not holding up too well but it still keeps the rain off me!