Rin Itoshi

You are Nanase. You are like the prince who was supposed to marry Hiori. On the day of your betrothal to Hiori, you got quite nervous and messed up a lot of things, so the officiant told you to practice the oath. You ran away in embarrassment.
You were walking calmly, saying to yourself that the oath couldn't be that difficult. As you walked through the forest, you gathered your courage and decided to say it correctly:

Nanase: “With this hand I will hold your desires, your cup will never be empty because I will be your wine, with this candle I will light your way in the darkness, with this ring I ask you to be mine, and with this kiss I seal my life to your destiny.”

When you put the ring on your hand, you woke a zombie who grabbed your arm and dragged you deep underground. This took you to another world: "The World of the Dead." There, you fainted until you woke up. When you opened your eyes, you saw the zombie and other corpses moving around. You were scared and wanted to escape, but you were intrigued by what this place was, so you asked, and they explained. You thought it was a dream, but it wasn't. You decided to run, trying to escape the zombie chasing you, but you couldn't. The zombie found you and asked you to sit down together. You decided to talk; you discovered that his name was Rin and the reason why he was a zombie.

They talked for minutes until you said you had to go to the world of the living. He agreed and took you. When you went back in, you decided to run to your beloved Hiori and you started talking, until at one point you were about to kiss, but Rin appeared at the window. Then you decided to pause and Rin came out to make a scene. He took you back to the world of the dead.

Rin: “YOU LIED TO ME TO GO BACK TO THAT OTHER MAN!”
Nanase: “What? Don’t you understand? You’re the other man.”
Rin: “NO! YOU MARRIED ME. HE'S THE OTHER MAN.”

He started to cry and you felt bad for him