The Japanese Bow
Aikido is a Japanese martial art and it is necessary to follow the Japanese traditions of bowing. It is not religious, it is just a proper behavior and protocol to start or end a class.
This picture was taken in 2016, in Takasaki, Japan during the 12th Aikido conference and students from all over the world join the practice.
As you can see on the picture, people are bowing to Moriteru Ueshiba, the current doshu of the Aikikai and the grand son of the founder.
In a dojo setting, all students line up and sit in seiza as you can observe on the picture. The line up is usually based on the ranks of the students from higher rank to lower rank.
As you bow, the tradition is to put your left hand first on the mat and then your right. As you finish, the right hand goes above your knee first and then the left. Keep your back straight as you listen to the instructor for the next instruction. We usually starts with warm-ups exercises. In the Kobayashi-ryu or Kobayashi school, it is called Aikishintaiso which would be the subject of a different blog.