Sasaki Saku (笹木 咲) is a female Japanese Virtual YouTuber and a member of NIJISANJI. Previously, she was a member of NIJISANJI Gamers' second batch along with Honma Himawari and Yamiyono Moruru. She is the first member of NIJISANJI to have retired and later resume her activities as a NIJISANJI Liver.

A sophomore high school student from Kansai with a laid-back attitude and a love for video games and aquariums. Her favorite animals are pandas and Japanese pancake devilfish. She is commonly referred to as (and prefers to be called) "Saki-chan" or by her surname "Sasaki."