The sign leaving Caribbean Beach in Kiryu (an indoor water park). When you leave, there’s an old man sitting at the door waiting for you to hand over the ticket that states you paid.
Caribbeaan Beach is great! It has three slides (one free, the others need a $5 wristband for unlimited rides), one ‘kids only’ slide, a lazy river, three hot tubs, a tidal wave pool, an olympic sized pool for laps, and a small kids pool that doubles as a shoulder massage for us older ‘kids’.
And, instead of brining your wallet, you get a wristband that will be scanned, and you pay for your purchase only when you check out.
I did wonder if there was an age limit on purchase scanning, since I can see kids racking up some serious ice-cream charges….