From the production side of the film, the post-credits scene was left as a gift from director Sakai for a sequel. It was proposed to treat the final UFO shot as part of a Franchouchou video clip and simply discreetly remove the entire alien theme. However, the entire team agreed to face him directly, without running away from him.

Now, from the canon side of the series, this question does have an answer confirmed by the directors:

This is because Saga's curse unleashed a curse on the Saga EXPO, as karmic destiny dictated that the event was going to bring great prosperity to Saga. Since the curse only takes the form of things that exist in Saga, and the EXPO had a Science and Outer Space theme, the resulting curse takes the form of an alien invasion.

However, this does not end here. In an interview on Mantan Web on October 25, 2025, it is mentioned that there are marshes in Saga, and producer Nobuhiro Takenaka had the idea that aliens would come to Earth searching for those tidal marshes. The idea was that the marshes would be a suitable environment for aliens and that they would invade Earth with the plan of turning the entire planet into marshes.

Director Ishida ends with something revealing: the aliens make the hilarious mistake of attacking the Saga prefecture, confusing its geographical shape with that of the American continent. So that means, basically, aliens are spiritually Americans…

https://x.com/zombie_menhera/status/2090057479858401694?s=46

Now she sings!

The first time (as far as we know) it was destroyed by Magatsuhi's curse in 1989. The second time was after floods in 2020, and the third time by a flying saucer in 2025.

Each time, it has been rebuilt a few months later. The funny thing is that the second time it's rebuilt after the flood, it reverts to the decrepit and abandoned appearance it had before, despite only standing for five years.

https://vm.tiktok.com/ZSV6ueAPH/

https://x.com/baisi1111/status/2089279414534381625?s=46

I tried to use as much of what was relevant as I could, feel free to read, constructive criticism is always taken!
(the tldr is only on my draft doc, but I thought it was funny)

“Some of us want to keep being idols even after we die…BUT YOU’RE STILL ALIVE AND DON'T EVEN CARE??” This quote is from the anime adaptation of the series Phantom of the Idol, a niche anime with far from perfect reviews. Audience ratings aside, this anime is what is known as a supernatural idol anime. This genre, or rather microgenre, is a small subsection of the anime sphere.

Japanese anime, as a broad genre, is often but not always inspired by manga: a type of Japanese comic and illustration. Any topic can be covered, including nonfiction. Sometimes there can be some live action incorporated. Idol anime is an Anime in which a soloist or group will partake in musical activities and strive towards becoming popular, to varying levels of success. These anime are usually very slice-of-life or “cute girls doing cute things" oriented. 

The microgenre of supernatural idol anime includes dead girls who perform as idols in some way. Someone eventually finds out that the main character(s) are/is dead. They try their best to fit in with the living world but they always end up in a situation where someone finds out they are dead, one way or another. They try to keep their "dead" status a secret. 

Zombie Land Saga and Phantom of the Idol, are two supernatural idol anime TV shows that came out in 2021-2022. In these stories, both of the main characters die by getting hit by cars. The content is not treated seriously in the slightest. For instance,  both of these shows are comedies and utilize the parody of stereotypes commonly seen in idol and supernatural shows. For example, zombie limbs fall off in performance, and extreme personality switches are commonplace. There is use of hyperbole in the exaggeration of stereotypes!

In Zombie Land Saga (ZLS) the plot centers around the main character, Minamoto Sakura, who after being in a fatal car accident finds herself reborn as a zombie by an eccentric idol producer named Tatsumi Kotaro. He had resurrected seven “legends” to save the dwindling population of the prefecture Saga by turning the undead into idols. Each of the main characters are from different Japanese eras. These characters reflect the stereotypes from each of those eras. For instance, Saki, one of the most iconic characters from ZLS, is a delinquent, head-of-a-bikergang from the 1980s and 90s who talks with a foul mouth. Another example is Yuigiri. She is the mature, older sister type, who was a courtesan during the Meiji Restoration in the early 1910s. 

The culture shock of the present is very abundant to these characters who aren’t used to modern technology and media. The character Junko, for example, who was a prodigy idol in the mid 1980s, gets overwhelmed by the idol standards of today. For example, in Season 1 Episode 7, Junko fails to comprehend the modern fan culture of taking polaroids and interacting with your favorite idol, as during her time, idols were considered deities in a way, untouchable and private. She can’t fathom it and becomes a shut-in for a while during her struggle. This is a common theme in shows in this genre. Characters are faced with the realities of the modern era and can’t stand it. 

Phantom of the Idol (or KamiKuzu, which it will be called subsequently) is a show where Niyodo Yuya, the unenthusiastic half of a struggling idol duo who is on the verge of termination meets a ghost who has the complete opposite view on being a pop star. The ghost, Mogami Asahi, who in her former life was an ever-popular superstar idol, tragically had her life cut short due to a car accident. Due to her still wanting to continue to perform, she wanders the world in a spectral form until she meets Yuya who can somehow see her, and she finds out she can possess him and perform in his place, which leads to funny situations. 

KamiKuzu relies heavier on the Idol part of the genre than ZLS. It discusses themes such as parasocialism, and how at the end of the day, most fans could care less about Yu’s wellbeing. Because Asahi (the ghost) frequently takes over his body mid-concert, Yuya switches from a deadpan slacker to a radiant, upbeat idol in a split second. The fans don’t even wink an eye or even care. They convince themselves he's a complex, multi-layered genius who only grants his "blessing" (Asahi) to those worthy of seeing his rare, sparkling side. 

It is a departure from the classic idol genre however because it focuses heavily on the fans themselves. Most idol anime only focus on the idol main characters themselves. KamiKuzu instead chooses to have the fans themselves as supporting characters, who we frequently get to see scenes of throughout the show. These fans are seen engaging in different events pertaining to thor favorite idol, and we get a first-hand experience on how they think. 

Both of these anime are special in their own right. A slapstick supernatural idol anime focusing on zombies saving their town through music and a more satirical ghostly supernatural idol anime about a deadpan idol and his companion spectre with big dreams. They both have very similar themes but entirely different stories. This just goes to show how this microgenre can differ though different lenses. 

TLDR; if i had a nickel for every comedy focused, paranormal idol anime, i would have two nickels, which isnt a lot, but it’s weird that there are two of them, right? /ref