An immortal character on the date Highlander (1986) was released.

– Dont raise your voice! I'll kill you if you make a sound.

– Would you please?

When a woman eats the flesh of a 人魚 (ningyo, litt. “human fish” but in Western context commenly translated as “mermaid”), she may become a 八百比丘尼 [yao bikuni], an 800 year^* old Buddhist nun granted youth and longevity.

 

^*The number 8 symbolises growth and prosperity. Larger numbers starting with 8 indicate that the amount is endless, comparable to saying “hundreds/thousands/millions of […]” in English. Therefore, 800 years can be understood as immortal.