We planned a trip and made a hotel reservation. But when we actually arrived, something surprising happened. At the time of check -in, he came across the person in charge of the front desk and said, “We have a problem with this reservation. There is only one room left.” However, we thought we had reserved another room. We were confused and checked the reservation confirmation to check again, but it was revealed that there was only one reservation. We immediately contacted the desk representative, “Why did this happen?” So the person in charge showed us a record of using the chat function. At that time, we only confirmed only a few seconds, and actually only made one room. We thought that we should reflect on the words, “Chat is convenient, but be careful,” we should reflect on and make a reservation after confirming more.