Fate/Grand Order

Everything starts with Alice making a new Ploy named "Only One/Number One - Shiny Star," which is meant to grant a wish with the restriction being that the wish has to be the "number one" wish and is the "only one" of that wish in the world.

However, with such a restrictive ruling, Alice deemed the Ploy a failure and never used it. That said, unused Ploy will fill up curses as time passes, and she can't let it overflow.

In 1997, she decided to dismantle the Ploy in a cottage in the mountain, but after knowing that there's Kumano Inn nearby, she decided to dismantle it there. However, during her stay, Shiny Star was stolen by a Kudan (a type of yokai) and taken to the owner of the inn, Kinomi. The Kudan then made Alice forget about the Ploy.

Unknowingly, Kinomi was made to use Shiny Star in his dream, activating the Ploy. In response, the Ploy decided to power itself by granting other people's wishes first. This led to the creation of the 5 Secret Baths, which will grant one specific "wish" to the people taking it, but they then will be killed by another version of themselves.

Two years later, in May 1999, after learning about the changes happening in the Kumano Inn, Alice remembered her stolen Ploy and decided to go back there to retrieve it, this time with Soujuuro along with her. However, at the same time, Shiny Star managed to grant five wishes, thus powering itself enough to finally fulfill Kinomi's "wish." And as part of its nature, Shiny Star tries to make Kinomi's "wish" a "Number One" which it tries to achieve by gathering and denying all wishes humanity makes, thus making Kinomi's the only "wish" to exist therefore a "number one." However, without their wish or drives, humanity would stagnate and simply die out, leading to world's destruction.

Alice tried to stop the Shiny Star but failed, and Soujuuro died as a result. The Shiny Star was already beyond her control, turning the whole area into a Singularity.

Sometime later, Aoko appeared and tried to stop Shiny Star, much to no avail, so she decided to do her usual procrastination tactic and send the Singularity to the future to be dealt with later, erasing everything that happened there on that day, delaying it from happening by 2 years.

Two years later, in 2001, Shiny Star "once again" tries to activate by granting people's wishes via the Secret Baths. Knowing this, Aoko tries to prevent people from using the Secret Baths, not letting it to power up as much as it did prior. This is when Aoko meets up with Fujimaru and Mash and agrees to work together with them. Also, since Soujuuro had "died" previously, Fujimaru ended up summoning Soujuuro as a Servant, registering him to the Throne of Hero (though he can only summoned by Chaldea). Aoko also secretly meets up with the adult Soujuuro, who had come here with Alice, and forcefully warped him back to Tokyo.

The group then successfully defeated the Kudan, which was behind many of the problems happening in the inn. At the same time, throughout the course of 4 days, Aoko succeeds in preventing 3 out of 4 people from taking the Secret Baths, albeit they keep on dying as a result. However, on the 5th day, Aoko, thinking that Kudan has been defeated, took the 5th Secret Bath that supposedly heal shoulder pain, and stupidly got killed by a copy of herself. Turned out, the Kudan's influence still persist because a piece of it is still within the Shiny Star.

After much talk, the group successfully got their hand on Shiny Star. All left is to dismantle it, and Aoko can go ahead undo the Singularity to prevent the world's destruction.

However, there was one catch. Although the Shiny Star's activation can be prevented this way, Soujuuro's death would still take place. With this in mind, the only way to stop the world's destruction while also erase Soujuuro's death was to destroy Shiny Star before Soujuuro's death take place. Thankfully, since only 2 out of 5 wishes was granted, Shiny Star's power won't be as strong as it was when Aoko first fought it.

As such, the group went to year 1999 Singularity and fight the Shiny Star. However, even in a much weaker state, the group wasn't able to even land a hit on it. The only way to make it vulnerable was to make the wish its trying to grant invalid.

So, Fujimaru ask Kuomi what was his wish, and after much struggle, Kuomi confess that his wish was to make his favorite idol, a certain really minor idol who recently passed away to be the number one idol. Kuomi himself thought that his wish won't be granted because the wish as to be "the only one," but as cruel as fate can be, Kuomi truly was the only one who wish for that in the whole world. And since it truly is Kuomi's deepest wish and it's not easy to change that, the situation seems dire.

However, one crucial factor was changed since Aoko sent the Singularity 2 years into the future. That was the fact that Tobimaru was actually hired by the father of the idol to deliver back all the fan letters Kuomi sent to her, and through his investigation on the idol, Tobimaru himself became a fan of her. So while it was true that Kuomi was the only one who wish for the idol's success in 1999 when the wish took place, Tobimaru in 2001 now hold the same wish. Meaning, the wish is no longer an "Only One," thus invalidating the wish. With the Shiny Star now vulnerable, the group successfully destroy it, preventing the world's destruction and erasing Soujuuro's death.

With everything is solved and everyone bid their farewell, Aoko undo the Singularity, returning everyone to where they originally belong. Soujuuro who was summoned by Chaldea follow Fujimaru and Mash to Chaldea. Though, when the three return to Chaldea, they were greeted by Aoko who got her way to Chaldea by catching Fujimaru and Mash's signal.

This is where Aoko reveal that she shouldn't have had the leeway to move the entire Singularity into the future during her first fight with the Shiny Star, so she suspect that Soujuuro must've done something. Although Soujuuro never actually confirm it to her, it was then revealed to us reader that Soujuuro had used his secret technique, which what became his NP, to land a hit on the Shiny Star, at the cost of his own life, staggering it long enough for Aoko to move the Singularity to the future.