The Maison Ikkoku tennants throw a party to celebrate the marriage of Yuusaku and Kyouko. However, during the party Yuusaku hears that Kyouko is waiting for a letter. He becomes jealous and begins to doubt Kyouko, worrying that she still loves someone else. When the morning arrives, the answer to his worries is revealed... (Source: AniDB)

Following their heroic efforts at Walter Park, the students of the misfit class return to Babyls Demon School after their summer vacation. What awaits them is not only adoration and admiration but also the shocking revelation that, in order to stay in the luxurious Royal One classroom, the entire class must be promoted to Dalet rank before entering the second year. As the Harvest and Music Festivals are right around the corner, there seem to be ample opportunities to rank up. Doing so will not be simple, however, as no class thus far has managed to accomplish such a feat. Hoping to give the misfit class a chance to achieve the improbable, the school appoints special tutors to aid in confronting the challenges that lie ahead. With his sights set beyond Dalet, Iruma Suzuki decides to take strides toward the goal of ranking up, starting with gaining acknowledgement from his special tutor: the short-tempered and selfish Bachiko Barbatos.

Yotsuya and Ichinose are enjoying a hot afternoon when they recall the time that the tenants of Ikkoku-kan and Mitaka go off on a cruise to party hard aboard Mitaka's new boat; however, the boat falls apart, and everyone is shipwrecked on a deserted island. With everyone up to their usual antics and shenanigans, what can happen in such a desolate place?

Fourteen-year-old Iruma Suzuki has been unfortunate all his life, having to work to earn money for his irresponsible parents despite being underage. One day, he finds out that his parents sold him to the demon Sullivan. However, Iruma's worries about what will become of him are soon relieved, for Sullivan merely wants a grandchild, pampering him and making him attend the demon school Babyls. At first, Iruma tries to keep a low profile in fear of his peers discovering that he is human. Unfortunately, this ends up being more difficult than he expected. It turns out that Sullivan himself is the chairman of the school, and everyone expects him to become the next Demon King! Iruma immediately finds himself in an outrageous situation when he has to chant a forbidden spell in front of the entire school. With this, Iruma instantly earns a reputation he does not want. Even so, he is bound to be roped into more bizarre circumstances.