Gender: Female

Age: N/A

Occupation: Housewife

Hometown: Tokyo

Yukie Sakamoto is Ryōta Sakamoto's mother and Hisanobu Sakamoto's wife.

Prior to the series, Ryōta constantly rejected his mother's attempts to get him a real career outside of gaming, and tried to get him to stop being a NEET. Ryōta would often hit his step-father and scold his mother during their arguments. Eventually, it is revealed that Yukie nominated her son to be put into the island simulation by Tyrannos Japan.

After Ryōta has been on the island for a few days, Yukie is shown to have harbored a great amount of guilt from nominating her son to the Btooom! game. From the guilt of nominating Ryōta, Yukie attempts to commit suicide by slitting her wrists with a razor blade in the bathroom. However, Hisanobu finds her when he arrives home, covering her wounds with a towel, going to call an ambulance but stopping to listen to her confession. She reveals that she nominated Ryōta to be a part of the Btooom! game as she knew her husband had been laid off his job, so will be unable to support the family and also due to Ryōta's poor treatment of her and Hisanobu. After this, she apologizes to both her son and husband.

(Source: Btooom! Wikia)