A very basic activity useful at the beginning of the year.
The students can fill in the small profile about themselves. 'My name is Taro. I am from Higashi Shogakko. I like Mario. Nice to meet you'.
Then walk around the classroom, make pairs and have short self introduction conversations. After the conversations they sign each others papers.
When demonstrating it is important in emphasis that it is not a race. It is important to have the conversation and not just collect the sign. The goal is to get to know your new classmates a little bit. the signs can be simple or fancy and they can be English or Japanese.
Set a time limit and let them go.
Additional rules could be getting signs from boys and girls and collecting signs from kids who went to a different elementary school. Also getting signs from at least one teacher.
nice, great for the beginning of the year