Brazil is home to the largest Japanese population outside Japan.
I bet they brought a couple of Japanese words to Brazilian Portuguese too.
The two that comes to mind is rock-paper-scissors, which we call "jokenpô", that is similar to the japanese 'jankenpon'. Chopsticks are "hashis" like already mentioned.
Also, we call soy-sauce "shoyu", which is the japanese for soy.
Despite the clickable name, they are perfectly fine. If they weren't, the entirety of latin america wouldn't be using them. The worst case scenareo is if the house doesn't have grounding. In that case you can get a lil' zap when closing turning the shower off while wet. I remember when growing up, my mom would rent cheap apartments in the beach for us to stay a few days during the holidays, and she always made us shower while wearing flip flops to avoid getting the lil' zap. I'm not entirely convinced this worked.