Bisuke is a 57-year-old woman who appears to be a 12-year-old girl. She is a master and experienced teacher of Nen, continuing the training that Wing provided to Gon and Killua during the Celestial Tower arc.
As a Treasure Hunter, Biscuit has a passion for collecting rare jewels, often getting very excited about them and even naming them. She also enjoys making money.
Biscuit has a devious personality. She uses her innocent appearance and demeanor to gather information, get what she wants, or gain an advantage in combat by acting helpless. However, when it comes to teaching Nen, she adopts a stern and serious attitude towards her students.
Initially, she aimed to destroy Gon and Killua's friendship, but by the end of Greed Island, she privately acknowledges that she has developed parental feelings toward them.
(Source: Wikia)
