You can do a psychological test according to the flag inserted on the mustard sauce sushi:
Skull-headed flag: the most honest person who can't tell lies. I don't like and am not good at deceiving others, knowing that telling the truth will hurt each other, but I still won't lie.
question mark flag: He is a habitual liar. In order to cater to others and please others, people often lie unconsciously.
Tongue-sticking flag: He is a terrible liar. You may often cheat others, but they are harmless little jokes, and you will soon be seen through. You are naive, innocent and simple.
smiley face flag: it is a professional ace liar. The expression and attitude can be confused, and there is no flaw. Every lie is very successful, which often makes the other person suffer a great blow after knowing the answer.
bomb flag: a person who seldom tells lies, doesn't want to bother the other side and won't cheat others. However, if it is on a special occasion, it will be expedient to tell a beautiful lie.