Also called Atarihenka.
Henka is an expression of Bad Sumou. A Rikishi does a Henka by moving fast or jumping to the side at the Tachiai. This in hope of catching a charging Rikishi unprepared and making thus lose by directly tumbling to the ground, or by Hatakikomi, or Okuridashi or the like.
It is Winning not by Power but by Trickery and is therefore worthless.
Henka can be an expression of:
1. Shortterm Strategy. 2. Longterm Strategy.
As an expression of shortterm Strategy it is done so that the Rikishi can win the current Shoubu.
As an expression of longterm Strategy the reason for it is not immediately connected with Winning the current Shoubu. A Rikishi employing Offensive Sumou might go for Henka from time to time. This in order to make other Rikishi not charge so strongly at the Tachiai. That way then when he charges strongly he will have a Power advantage.