“Aniki” is a Japanese word for “brother” or “bro”, who is older or looked up to as a superior to the other party.
The term/word came from the Japanese Mafia Yakuza and Gang tradition of the young, wild Japanese guys, where they show their respect for a leader who was there for a longer time than them, but he is not a boss yet, expect if it’s a gang where the leader is called “aniki”.
It became a meme thanks to Billy Herrington, who was an adult film actor, who lived in Japan and used to play in Gachimuchi, but sadly, he died in a car accident in 2018, when he was 48 years old.
The word “aniki” is used in the Japanese culture as a word of respect and in anime, manga, and games like the Yakuza series, so it is quite heavily spread.
It’s popularity on internet started spreading in the western world when Billy Harrington became a meme.v
- Yakuza Wiki – Aniki