When suddenly, I realized I heard those names somewhere before:

In this Chinese anime (which is awesome btw, 9000/10 would recommend), the main character's name is Jiang Haoyi! And you would not believe the parallels in the stories:

MAJOR SPOILER WARNING. WATCH THE ANIME AND THE OSP VID BEFORE PROCEEDING

1) The story starts off with the Jade emperor and his 10 sons who turn into 10 suns and start roasting everything. So the JE hires Hou Yi the archer to fix it and Hou Yi shoots 9 and leaves the one flaming ball of gas we all know and love. Horrified that he only has one kid left, JE exiles Hou Yi and his wife Chang'e to the earth and leaves them mortal, which they both hate.

In the anime, the main plot is Haoyi and a bunch of girls ate a magic chocolate cake together that a love goddess, Mei Tata misplaced. Because of the chocolate, Haoyi now finds himself with multiple girls thinking they all have a relationship with him. Since the girl's aren't exactly quiet about it, the surrounding guys and teachers find out and Haoyi's life soon becomes a living hell, much like Hou Yi's sitch. As a result, Haoyi now has to break the spell by honing in on each girl's one true desire and fulfill it, much like an archer aiming at a target. Also, Haoyi has a yandere childhood friend named Xueli after him who, like Chang'e, is now dealing with new problems (the harem) due to magic and being associated with Haoyi.

2) Meanwhile, Hou Yi and Chang'e are finding themselves on a time crunch to become immortal again because they're both slowly developing an existential crisis. Hou Yi then sets off on a quest to find a way to cure them.

In the same way, Haoyi is also on a time crunch because as it turns out, the magic gets stronger over time and makes more relationship stuff come true (one of the girls actually have two grown children with Haoyi because of this). Not to mention the girls' feelings play a strong role in the story just like Chang'e's hatred of mortality. Chang'e's desire to return to the better world is also similar to Sandy, a popstar who somehow also ate the magic chocolate and wanted to leave the earth for a better world of her own creation.

3) So, Hou Yi 1.0 goes on a quest to get the elixir of immortality from the Queen Mother of the West. He has to pass multiple trials on the way and feeling sorry for him, she hands it over but warns him that it's a limited supply.

In the anime, Haoyi gets help from the clutzy love goddess Mei Tata who fills him in on how to stop the magic. In a way, each situation proves to be very much like a set of trials he has to face.

4) So the deal with the elixir in one version of the story is that the dose the QM has on hand is only enough to either make 2 people immortal or one person a god. Also, it's the couple's only chance because the peaches it's made from only grow once every 6K years. (Why they couldn't just take the immortality and wait 6K years for Gold Membership, I have no idea). In this version, Chang'e misses godhood so much that she takes all the elixir for herself.

In the anime, Haoyi doesn't really deal with immortality, but the relationships themselves are analogous to this. Just as Hou Yi would be satisfied with simple immortality but Chang'e wants the whole package, Haoyi just wants the girls to forget him and go back to how they were before the spell, but it turns out they still remember that he fulfilled their greatest desires even after the spell is broken and want to be in a full on relationship with him. Basically, they aren't satisfied with going their separate ways and instead want the full package.

5) In the version where Chang'e gets greedy with the elixir, she flies up to heaven but is still exiled but can't go back to earth so she has to settle on the moon

Meanwhile, the girls are in a midpoint themselves since they aren't under the spell anymore but they remember everything Haoyi did for them and are now in love with him for real. Also, because of how harem anime works, they're all stuck with Haoyi in the middle unable to decide who he wants to be with.

Bonus: In the "bad end" Hou Yi gets offed by his apprentice just as Haoyi almost gets offed by the mob of his angry classmates.

6) Meanwhile, the "good ending" has the QM give Hou Yi only enough elixir for one person but neither Hou Yi nor Chang'e take it because they don't want to leave each other. So they agree to have Chang'e lock it away in their cabinet for later, but one of Hou Yi's apprentices hears about this elixir and tries to steal it. Rather than let him have it, Chang'e sacrifices herself by taking the elixir herself and ascending to godhood and choosing to be on the moon while keeping a really long distance relationship with her husband until he dies.

Multiple of the girl's stories are actually analagous to this. Sandy had to deal with a jerk of a childhood friend/boyfriend who hated how embarrassing her childlike innocence was and only hung out with her for money (kind of like the apprentice chasing after the elixir). Of course, the going-to-another-world thing also shows up again and the harem anime decision crisis basically becomes her moon.

With Xueli, the yandere from before, something similar happens where a guy from her past who basically broke her mental state into becoming the yandere she is today comes back with further intent to use her for his gain. Xueli's becoming a yandere as a result of this jerk's actions is also similar to the immortality in the original tale. Not to mention she too tries to be as close to Haoyi as possible.

In fact, some jerk pushing the girls into going to another world/state of mind/life point seems to happen with all of them since they each have their own catalysts to making the magic grant their love wishes. One had a neglectful father and she ended up believing she was pregnant with Haoyi's child. Another was a straight up tsundere sports girl who has to hide that she's a cosplayer and has to keep her soft side hidden from her friends while keeping the other girls off Haoyi. And the one with fully grown children had a stepdad who couldn't handle the fact that she wasn't his daughter and pushed her out of his life, leading to a strong desire for a family life she likely wasn't ready for.

7) Finally, moon cakes that are offered to Chang'e every year during the festivals remind me of the chocolate cake that started this whole thing.