Mai Shiranui is the granddaughter of Hanzo Shiranui, a master of ninjitsu and Koppo-ken. She is the childhood friend of Andy Bogard and is determined to be his wife some day. She is a trained Kunochi.
The granddaughter of Hanzo Shiranui, a master of ninjitsu and Koppo-ken; she was originally trained by her father in ninjitsu as well as by Jubei Yamada. Afterwards, she sought to learn the secrets of Koppo-ken from her grandfather and it was around this time that she first met Andy Bogard (the younger brother of Terry) who had also come for training under Hanzo Shiranui. Reputedly, Mai was originally uninterested in Andy and thought of him as merely another callous man who was obsessed with his training. This later changed when she received a present on her birthday from him and she quickly fell in love with him afterwards and has proclaimed herself his fiancee, much to his consternation.
Mai is eager to reunite with Andy Bogard upon learning he has returned to Japan. She confronts Master Jubei Yamada who informs her that Andy is training down by the river. As Yamada has not seen Mai in quite some time he expresses his joy at how beautiful she has grown up (and gropes her breasts). Mai takes offense to this and smacks the man down. She then finds and confronts Andy about deserting her (his fiance) without so much as a word. Andy is quickly taken aback (fiance?) and she knocks him down on his back with a flaming slash. Joe Higashi arrives at that time as well with the news that Andy's brother Terry Bogard has been defeated. Mai tries to get in another cheap shot but Andy lauches her into the river with an air rendering bullet.
At dinner Master Jubei spews his beverage all over Joe when he learns that Wolfgang Krauser is the individual that has bested Terry. He then proceeds to tell the group the history of the Stroheim family. Andy is determined to face Krauser but Jubei insists that he is not ready. The two have a fight (If Jubei wins, Andy stays. If Andy wins, he goes) with Andy scoring the victory over Master Jubei. Jubei instructs Mai to go with Andy but not to let him fight Krauser.
Mai and Andy go to Germany but learn that Krauser is escorting some European Royals and is not at the castle. Lawerence Blood sees the pair and follows them determined to find out what they want. He and Mai fight with Mai score several major hits but she is finally overpowered by Blood. Seeing Mai strung up enrages Andy and he makes short work of the second deadliest fighter. Mai senses that Andy does truly care for her (as more than just friends). When Joe is injured by Krauser Andy makes Mai promise to stay and take care of him. Terry later arrives and asks her the same which she does.
Mai begins the film attending Joe's fight against the reigning Muay Thai champion Hwa Jai. She is initially very worried about Joe as he is not putting up much of a fight. However Andy informs her that he is faking. When Haw Jai tries to deliver a right cross Joe hits him with a knee thrust that knocks the (now former) champion out. Mai and Andy are at Joe's celebration party and meet Terry's friend Kim Kaphwan who is there with his family. Mai thinks the boys are adorable and gives Andy a glance (which terrifies Andy). She is present when a large masked man appears chasing a young woman.
Kim defeats the masked man, later revealed to be Cheng Sinzan, and learns from Sulia Gaudeamus that her brother is behind the attack on her. He is looking for the 3 remaining pieces to the Armor of Mars. Andy and Mai travel to Turkey in search of the armor piece but it turns up missing. Joe arrives and gives them the news that their piece was missing as well but it might be in Germany. Andy deduces that their missing piece may have ended up in China (at Master Tung's school) but they don't know where to look. Joe deduces Master Jubei might as he and Master Tung were close friends.
At the club where Master Jubei is handing out (with many lovely young ladies), Mai is accosted by Hauer. Hauer finds her very beautiful and Mai acknowledges his good looks but states that Andy is cuter. Hauer departs the scene as he is vastly outnumbered. At the school Mai fights Hauer but is soon bested by him. When Andy arrives on the scene Hauer uses Mai to his advantage and best Andy. With the location to the final armor fragment in hand, Mai and Sulia have a girls night by the pool talking about the men in their lives. Mai gives Sulia the motivation she needs to pursue Terry (aggressively) and Sulia smiles and takes it to heart. The pair are attacked by Panni and Jamin and Hauer arrive with Terry and Joe who are both drugged. Sulia leaves with Jamin while Panni captures Mai. As Hauer closes in on her Andy arrives and makes quick work of him. Mai then dispatches Panni utilizing her Super Ninja Bee Attack.
The following day Mai, Andy, Joe and Terry track down Laocorn Gaudeamus and the group battle the would be god. Sulia is instrumental in Laocorn's defeat but the group learns that Gaudeamus himself was using Laocorn as his means to reclaim the armor. Mai, Andy and Joe must watch Terry battle the energy based god as none of them have the power to fight him. Mai does her best to console Terry as he has once again lost the woman whom he loves.
In the ONA series (based on the King of Fighters: Maximum Impact series), Mai encounters Athena Asamiya, Soiree Meira, and Iori Yagami. South Town is on fire and Soiree is trying to help the people. After Iori knocks over a young girl in his way without so much as acknowledging the girls existence, Mai watches as Soiree and Iori fight. The fight moves to a deserted church and it literally brings down the roof on all present. Athena manages to keep the rubble off of them and Mai uses her flame attack to disperse the rubble. Mai watches as Soirre digs for Iori but they later learn from Alba Meira that Iori has left South Town.