As the Minor Gay Love Rival in Het Novels - Chapter 9.11

A 21st-century tech manager, accidentally thrust into the body of Emperor Commodus—yes, the infamous villain played by Joaquin Phoenix—has one goal: not to die like him.Armed with his wits and a hyper-intelligent AI on a solar-powered laptop, he must navigate the treacherous politics of ancient Rome. Everyone, including his own sister, expects the arrogant, decadent tyrant. Instead, they find a calculating reformer. But as he tries to avert the fall of the empire, he discovers that being a “good” emperor might be even more dangerous than being the monster everyone is waiting for.

~She is a waste daughter from the Su family that couldn’t cultivate. On the day before her wedding, the Third Prince breaks off their engagement in the street. Her own sister replaces her in the marriage to the Third Prince. She became the center of gossiping in the city. In her resentment, she hits herself on the Su Family’s gate, only to become the object of other people’s ghost marriage.

She, Su Zimo, open her eyes to find herself sleeping in a coffin. It’s not to surprising seeing as she put herself here (hit head on gate), but why is there another person lying beside her? And whats more they are wearing red wedding clothes. After taking all this in she almost faints.

~He, is a cursed person with an indescribable status. This curse that has been passed down in his family for centuries is now effecting him.

A mistaken ghost marriage, a battle in business, and a long period of painstaking love, made their fate intertwined.

- Description from Novelupdates

A young man woke up to a world of magic and endless possibilities.He was transmigrated.Great!Only that he now had three huge problems.One, he had no memories of his past.Two, he was a villain destined to die no matter the outcome.And three, the heroines were all kinda... should he say, obsessed?Yeah, he was fucked.[Note]No Yuri.Conflicting emotions of MC due to loss of memory for the first part.Huge plot twist, so don't fall for whatever you see.NTR? Not.But probably netori.Beta MC? Big No.Harem? Yes! Don't ask me how but I'll make it possible.

High-school student Koremitsu Akagi finds himself attending the funeral of Hikaru Mikado, who had died in an accident during Golden Week. He’s not sure why he’s there, as he only exchanged a few words with Hikaru at school. However, Hikaru doesn’t seem to be completely gone from the world, as he comes back as a ghost in order to fulfill a promise to Aoi Saotome, his fiancée. Since Koremitsu is the only one who can see him, he asks him to carry out his promise in his place.

Complying with his request, Koremitsu tries to fulfill Hikaru’s promises to the rest of his “girlfriends”, helping them overcome past misunderstandings and repair broken relationships.