In Aikidō, we encounter two fundamental principles that teach far more than they may seem to: irimi (入身) and tenkan (転換). Both are part of everyday training in the dojo and represent two ways of relating to movement, distance, and another person’s actions. By studying them, we learn to recognize when to enter, when to change our position, how to make use of the direction of force, and above all, how to act at the right moment.
Irimi means entering. In martial practice, it means advancing into the opponent’s space along a path that takes us off the line of attack and into a favorable position. It demands decisiveness, precision, and a clear understanding of distance. Entering too early may expose us unnecessarily; entering too late may allow an attack to be completed. The skill lies in recognizing the instant when our movement changes the conditions of the encounter.
Through training, irimi teaches us to advance with the whole body. The direction of the feet, the position of the hips, the orientation of the center, and our relationship with the partner must work together. A technically correct movement can lose its effectiveness when performed with hesitation, stiffness, or at the wrong distance. Deciding to enter must be accompanied by clear execution.
Tenkan means turning or changing direction. It is studied through a rotational body movement that often uses the forward foot as a pivot. The body changes its orientation and angle in relation to the partner, allowing the movement to be guided in a new direction. Depending on how contact is established and the technique is executed, this shift can help us use the momentum of an attack and disturb uke’s balance.
One of tenkan’s most interesting lessons is that direct resistance is not always the best answer. When force moves straight toward us, we can change our position and let it continue its course while seeking a more favorable situation. Doing so requires sound posture, mobility, and sensitivity to changes in the partner’s direction.
In Aikidō, these two principles can also complement one another. An entry may continue into a turn, while a change of direction may create a new opportunity to advance. The circumstances determine which movement is appropriate. Learning irimi and tenkan means developing the ability to choose a suitable response rather than being limited to a single way of acting.
This lesson takes on an especially interesting dimension when we bring it into everyday life. Some situations call for irimi: accepting responsibility, beginning a difficult conversation, making a long-postponed decision, or facing a problem that requires our involvement. These are moments when moving forward clearly can transform a situation.
Other circumstances call for tenkan. A discussion that escalates, a difficulty that seems to have no solution, or a project that meets obstacles may require a change in perspective. Insisting on the same direction can consume time, effort, and opportunities. Changing our approach can reveal alternatives and allow us to respond more intelligently.
Training helps us recognize these differences through concrete experience. We learn that decisions must be accompanied by attention, that flexibility requires discernment, and that every situation has an appropriate moment for action. Irimi develops our capacity to advance with determination; tenkan, our ability to change course without losing our purpose.
In the dojo, we study these principles with the body, through movements repeated and refined over many years. Outside it, we can recognize them in our decisions, relationships, and ways of facing difficulties.
Sometimes we need to enter. At other times, to turn and find a new path.
True learning lies in recognizing what each situation requires and acting at the right moment.