Sayuri Kinniku, also rendered as Kinniku Sayuri, is a recurring character in the anime and manga series Kinnikuman. She is the mother of the protagonist Suguru Kinniku, better known as Kinnikuman, the wife of King Mayumi Kinniku, and the fifty-seventh queen of Planet Kinniku. She is a native of Planet Kinniku and is classified as a Seigi Choujin, a justice-oriented superhuman. Her most recognizable visual trait is the word "Mama" written across her forehead. In the original manga and the first anime series, she was usually referred to only as Mama, and her given name of Sayuri was established during the anime adaptation of the throne succession storyline, later being carried over into the sequel series as well. In both anime productions she was credited as Queen Kinniku.

In terms of personality, Sayuri is generally portrayed as a devoted and long-suffering mother who is affectionate and caring toward her children. Beneath that warm exterior, however, she has a spirited and strong-willed nature. She frequently dominates her husband, cutting through his foolish behavior with sharp retorts, and she is not intimidated by danger. During her sons' matches she can become an intense and even aggressive supporter, going as far as using Mayumi as a prop to demonstrate techniques for Kinnikuman. Although she is normally indulgent and loving, when she is truly angered she shows no mercy, even toward her own son.

Her motivations are centered on the wellbeing of her family and the honor of the Kinniku royal house. Early in the story, after Kinnikuman's reputation had been damaged, she disguised herself as him and fought a giant monster, destroying it with the Kinniku Beam in order to restore his good name, which demonstrated that she shares the Kinniku family's ability to grow to colossal size and is willing to enter the fray herself. During the contest for the succession to the Kinniku throne, when the Five Princes backed by the evil gods appeared, she cut her own arm with a blade to formally proclaim the tournament that would decide the rightful heir, and it was her decision that the competition would be conducted as a castle-capture battle. In the later stages of that tournament, she and Mayumi succeeded in deciphering the prophetic texts together. The anime version expands her participation somewhat, giving her scenes as a commentator during matches. In the Golden Mask storyline, she also calls out to the silver mask in the Kinniku grand temple and sends it from Planet Kinniku to Earth, a feat her husband notes she is especially skilled at. In the newer manga storyline she largely fades from the action, but in one later chapter she reappears briefly, watching through a door alongside Bibinba as Mayumi sheds tears of joy over the awakening of Nemesis.

Her most significant relationship is with her son Suguru, whom she raised with affection even while disciplining him harshly when necessary. She is the wife of Mayumi Kinniku, whom she often overpowers in personality, and the mother of Suguru and his brother Ataru. Through Suguru's marriage, she becomes the mother-in-law of Bibinba. In the sequel series, which takes place in a later generation, she has already died, leaving Mayumi a widower and appearing only in flashbacks and recollections.

In terms of abilities, Sayuri is a Seigi Choujin who can enlarge her body to giant size just as her son can. She is capable of using the Kinniku Beam and has fought giant monsters directly, showing that the queen of the Kinniku clan is herself a capable fighter. Her name, which was only fully established later in the franchise's history, is derived from that of Yoshinaga Sayuri.