The Final Decisive X'mas Battle!! 1

is chapter 185 of the Beelzebub manga.

Summary
In the final match for the semifinals, Kanzaki and Yuka step into the boxing ring with Izuma and Aoi.

Before the last match begins, Kanzaki and Yuka both reassure each other that they can go through any fight in the competition regardless of what it may possibly be; however, both fluster with embarrassment after Kanzaki subconsciously states that they will be fine even if a flirtatious battle comes up, while Izuma and Aoi look on with skepticism from the other side of the boxing ring.

Surprisingly, their fight is revealed to simply be a normal combative fight against one another, something that leaves both Kanzaki and Yuka speechless due to the fact that it an actual physical fight instead. The two complain to the commentator about the fight, and while distracted, they end up being taken down instantaneously by Izuma and Aoi with a single hit to both. Therefore, Izuma and Aoi are able to proceed to the finals for the title of "best couple".

Meanwhile, near the school entrance, a young man and a small girl arrive at Saint Ishiyama Academy Arc.

Afterwards, Aoi states confidently that her pair will not be able to lose to anyone as they have a greater goal in mind. However, she then learns that Izuma has no intention of participating further because Shizuka has already lost in the previous match. Outside, Aoi tries to get Izuma to compete with her again but ends up being rejected; upon this, she realizes what Izuma's true motivation for competing is. As she attempts to persuade him once more, she hears someone call out to her nearby, and to her shock, she discovers that the person is Izō Aiba from South Chinpira High School.

The finals for the Saint Saint X'mas competition then commence back in the gymnasium.

When Izuma and Aoi are selected to come up, surprisingly, Aiba and Aoi show up instead in a new combination for the finals. Aiba's presence shocked several of the students in the vicinity.

He explains that he came to see Aoi for Christmas and that he is now her new partner, something that is allowed by the officials in the competition due to an apparent emergency that Izuma faked for them. Afterwards, Aiba tells Oga that he is the strongest man in the universe because Aoi chose him to compete with her.

Suddenly, the event for the two couples commence and it is revealed to be another head-on battle between the four individuals, which is reviewed poorly by the spectators due to the nature of the previous event from the third round. Nevertheless, the event begins and the respective sexes of the two pairs clash with each other. During the fight, Aiba is revealed to be clad with Demonic power again just as he fights using his improved hand-to-hand combat skills. He even ends up taking down Oga with a specialized technique while Aoi strikes Hilda at the ground when distracted by their male partners. With both members of the Oga-Hilda duo momentarily down, Aiba takes away their gold star.

However, Baby Beel also steals the other team's gold star which results in neither couple being eliminated for the loss of their object, resulting the fight in continuing further.

Characters in order of appearance

 * 1) Taeko Furuna
 * 2) Hajime Kanzaki
 * 3) Yuka Hanazawa
 * 4) Aoi Kunieda
 * 5) Kaname Izuma
 * 6) Izō Aiba
 * 7) Chiyo Aiba
 * 8) Shizuka Nanami
 * 9) Hidetora Tōjō
 * 10) Beelzebub IV
 * 11) Tatsumi Oga
 * 12) Hilda
 * 13) Takayuki Furuichi
 * 14) Ryōko Asuka
 * 15) Chiaki Tanimura
 * 16) Ichirō Shinjō