The Three-Year Smile of Death (微笑み三年殺し Hohoemi san-nen koroshi?) is the ultimate Chinese Amazonian attack. It is driven by anger stored in the body for up to three years that is not released after enough tension is built up in the abdomen, the normal release for anger. Instead, this anger is manifested in numerous small and insidious ways against a target that appear to be accidents or minor ways to spite them, but all this time the perpetrator never appears to be angry at them. What appears to affect the target the most is the constant stress and worry created. The Three-Year Smile of Death is also suggested to be used exclusively by Amazon women against men.
Mousse suspected that Shampoo was using the technique against him when he accidentally detonated some fireworks on her and instead of hitting him like she normally would, she made light of the incident. Subsequent attempts by Ranma Saotome to determine her mood indicated that she seemed to be normal.
When asked about the technique, Cologne revealed that a pressure point could be hit to release the stored anger and declared that only Ranma could pull it off. However hitting this pressure point looks just like feeling up the target's rear end, which enraged Mousse and Akane Tendo. Ranma tried to hit the pressure point twice, but was thwarted by Shampoo turning around each time. When Mousse vowed to do it himself and appeared, Shampoo got mad at him and stomped on him. Cologne then declared that this had released the stored anger, preventing her from using the Three-Year Smile of Death. However Shampoo then revealed that she had no idea what the technique was. She had been nice to Mousse because she had tried to make up for washing his clothes with all his glasses breaking them.