The mingler is played in three rounds and can be done in two different ways.
Before each round do some repetition practice and give instructions such as different ways of responding. Also instructions such as make different pairs or boys pair with girls etc.
First round the students make pairs and ask for a signature. 'Would you sign your name for me?' and the response 'Sure'
Once they've collected three names they can sit down. This can be done with both kids getting signs or doing 'Rock, Scissors, paper' and the winner making the request with the loser responding 'sure' and signing the paper.
The second round they request 'Would you draw a .... for me?' Either the teachers decide what to draw or the students can decide.
The third round they request 'Would you write a message for me?' You can put a few message examples on the board. You can let them write messages in Japanese.
After this I have the students work in pairs or groups to complete the shopping dialogues, practice them and then present them for teachers. Depending on time and the class they can memorize them although most of the time we let them read the dialogues. I reward stickers if they do well.