Water temperature in Japan is considerably colder than the water temperature in Florida. Please acclimate water temperature before you let fish go swimming in a pond. You can acclimate water temperature by letting the bags float on the pond for an hour or so before opening the bags. If it seems to be desirable to recharge Oxygen, please recharge Oxygen and let the bags float on the pond. Also, you may want to keep the fish in 0.5% salt water if they look too much stressed from the shipment.