Bukiko Udou (兎洞 武器子, Udou Bukiko) is a member of the Gekka Hyoujin Kai (月下氷人会), abbreviated as Ge'hyoukai (月氷会), tasked with overseeing the second Jet Black Wedding Feast. Udou is the secondary antagonist of the Jet Black Bride Arc.
Udou is very violent, brutally attacking Konomi Mera and Kuroudo Iizuka without provocation, an act she considers "fooling around". She shows little in the way of sympathy, mocking Medaka Kurokami's horror at the idea of a second Jet Black Wedding Feast, and revealing that all six of her suitors are dead with a smile. Despite being affiliated with the Ge'hyoukai, Udou shows no deference to the Kurokami Group, openly relishing the chance to taunt Medaka. Despite her bravado however, Udou is easily cowed by Medaka's strength, and is shocked when the other girl states her intent to participate in the Jet Black Wedding Feast.
Udou has violet eyes, short, dark purple hair, and two matching colored dots on her forehead. She wears a dark blue leotard with a beige scarf. The leotard also has a white bunny tail on the back, and Udou also wears long, ragged white bunny ears on her head. She wears elbow-length, dark red gloves with zippers down the side, and knee-length boots with a similar design and color scheme. Udou has a tattoo on each shoulder.
Jet Black Bride Arc
Udou appears in the Hakoniwa Academy cafeteria, having brutally beaten Mera and Iizuka so stealthily that a conversing Medaka and Kamome Tsurubami did not even notice. As she waits for them to notice her, Udou eats a piece of meat. When Medaka notices her, Udou tosses Mera aside and introduces herself as a member of the Ge'hyoukai, and claims she has great news. She claims that she knows nothing of what happened three years ago, but reveals that there will be a second Jet Black Wedding Feast held now that Medaka is sixteen. Questioned by Tsurubami, Udou tells him that all the original suitors are dead, and that new suitors from each family have been selected; she has in fact come for Tsurubami, not Medaka, to invite him to the Jet Black Wedding Feast. Udon goes on to explain that everything is for the growth of the Kurokami Group, and that once a suitor is selected, the marriage will take place immediately. She turns to Medaka and tells her that once the process of elimination is over, she will be expected to drop out of school, and that she should make no complaints. Udon is shocked when Medaka destroys the tip of her spear with just wind pressure, and is further amazed when Medaka declares she will enter the Jet Black Wedding Feast.
Before leaving, Udou tells Medaka and Tsurubami that they need to find four more people to join them. Later, Udou meets the All Jokers on the aircraft carrier Black, the greatest piece in her collection, and the stage for the second Jet Black Wedding Feast. Udou explains they need to be on the sea because it is a neutral zone. Udou leads them into the ship to meet Medaka's suitors. When Medaka moves toward Kairai Kugurugi, Udou gets between them, stating that taunting is not allowed. She then explains that the second Jet Black Wedding Feast is a six versus six elimination battle; the first team with six victories wins. She goes on to state that if Tsurubami's team wins, then Medaka's ties to her suitors will be cut, while if the Sub-House Joint Team (Udou accidentally begins to call them the Pervert Team) wins, a final round to decide everything will be planned. Udou is stunned by Najimi Ajimu's easy defeat of the six suitors. Udou admits that the six men were only doubles, and apologizes for tricking the group. She reveals however that doubles were not used to test the outsiders' strength. Pressed by Ajimu, Udou admits that the real suitors actually overslept. Udou is put out by how easily Misogi Kumagawa brushes off the real suitors, and wonders how they will respond. She is somewhat unnerved by one suitor's suggestion.
At the Black Bunker, the Kurokami base in the South Pole, Udou is seen in a winter coat, remarking on how cold it is. She asks a chained Medaka is she should raise the temperature; when Medaka declines, a smiling Udou tells her not to push herself too hard, as the wedding feast has just begun. Udou tells Medaka to behave and in return, Udou will keep her companions safe, including the new ones coming to rescue her. Udou adds that they will be captured immediately, of course. Udou is confused by Medaka's happy face despite her reprimands for Zenkichi Hitoyoshi. Udou reviews in her head all the information the Ge'hyoukai has gathered about Zenkichi, and wonders if Medaka has fallen in love. Shaking the feeling off, she checks with Medaka, asking her whether Zenkichi might be coming to save her because he loves her. Medaka shocks Udou by revealing that Zenkichi had already rejected her. Hearing Medaka's story, Udou panics, though she hides this from Medaka. Worried that Medaka will soon realize she is in love with Zenkichi, Udou decides that the two must be kept from meeting. She approaches the suitors, telling them that they will be moving to the third stage, only to find one suitor absent. Asking where the woman is, Udou is told that she has gone "plane crashing".
On Kuromaku Island, Udou, Medaka, and the remaining suitors prepare to leave for the moon. Medaka makes a play on words concerning Ge'hyoukai, annoying Udou, who in turn asks if she understands the situation she is in. Udou presents Medaka and the remaining suitors with her rocket, Black Light. Udou questions Medaka's feelings on Zenkichi, though when Medaka tells Udou that her efforts are futile, as Zenkichi will catch up with her no matter what, Udou loses her temper. She demands to know how Zenkichi will catch them in space … just as a jet crashes into her rocket. Udou is shocked to see Zenkichi, and horrified that her one trillion, seven hundred billion yen (twenty-one billion U.S. dollars) rocket has been destroyed. Udou is disturbed by Medaka's reaction to Zenkichi's arrival, but tries to remain calm. As Zenkichi delights in Medaka's acceptance of his proposal, Udou runs Zenkichi through with her spear. Sweating profusely, Udou blames Zenkichi, claiming he forced her hand by coming to the Jet Black Wedding Feast, and remarks that this event is similar to what happened three years ago. Udou is surprised when both Zenkichi and her spear disappear. Udou tells those assembled to wait until the rocket can be prepared, only to be confronted by the entirety of the Student Council. Udou listens to Momo Momozono's offer for a release of the hostages, with conditions. As the final round begins, Udou looks anxious.
The group makes their way to another area to start the final round. Udou unlocks the door to the new area. To determine the order of turns in the game, Udou holds out four cards for the players to select. She also sets up a table for the players to sit at. After Namanie Nienami accuses Medaka of cheating when she leaves the room, Medaka has Udou join her outside. Despite Sui Kanaino's complaints, Udou admits that Medaka is doing noting in violation of the rules, and therefore she cannot stop her. When Momozono reveals that Fukurou Tsurubami was killed by the overseer of the first Jet Black Wedding Feast, Udou looks mildly uncomfortable. As the audience discusses each player's standing, Udou shoots down Kudaki Torai's attempts at discrediting Momozono's seemingly assured victory. Udou listens on as Momozono reveals Medaka's true plan; to force the suitor to end with "surrender" by manipulating the entire audience not to use the necessary syllables.
Unknown Shiranui Arc
Udou calls Kumagawa from Kuromaku Island and asks that he put Medaka on. Udou explains that the moon is falling towards Earth. She then passes the phone on to Momozono.
Bouquet Toss To The Future Arc
Weapons Specialist: Udou carries a spear longer than she is tall. She seems quite proficient in its usage, as she was able to brutally beat both Mera and Iizuka so stealthily that neither Medaka or Tsurubami noticed. The spear's tip is destroyed by Medaka. On the aircraft carrier Black, Udou is seen with a new spear. This spear is later sealed inside a card along with Zenkichi's body by Momozono. She is seen with another new spear when leading the remaining suitors and Medaka's allies to a new area for the Jet Black Wedding Feast's final round.