- "My condolences."
Riddle is the first Undertaker in the series, and also the main protagonist character. His contractor is Hayato Sakura. Riddle is the one responsible for preparing funerals, while Hayato catches the spirits.
Riddle is tall with long blonde hair, green eyes and a beautiful face. His physical appearance is a 20 years old man. Riddle wears the Undertaker's uniform and a blue tie with stripes on it. He wears a hat with feathers and red roses. He also wears earrings.
PersonalityEditRiddle is cool, calm, and mysterious. He likes teasing Hayato, treating him like his own toy. He is kind of sadistic, always wanting to make Hayato suffer in physical ways since he loves to see him cry instead of smile. However, Riddle actually cares about Hayato and will save him anytime he needs help. Riddle is also shown to be jealous when Hayato gets close with someone else. He also tends to get really possessive of Hayato but usually use the excuses 'possession' or 'toy'. On the other hand, Eve had also mentioned that Riddle easily gets bored of someone, as he was frequently changing contractors. Riddle is intelligent but at moments he seems to almost doubt Hayato's friendship/caring side for him in earlier chapters - saying that he finds friendship useless and the contractor/soul bond is the only one he needs.
It is also shown that he has a complex with Hayato, uttering that 'You're not ready to satisfy me yet...' or 'Perhaps you don't even see me.' He only realizes that Hayato actually cares for him at Chapter 26, when Hayato voices his feelings out.
He made a contract with Hayato because he possess the Twilight Key. Riddle wants Hayato to become the King of the Catacombs. He had secretly protected Hayato since he was a baby, long before they even met. When Hayato was a small child, not that many spirits tried to attack him and Riddle could deal with them alone. But when Hayato grew up, the Key's power had probably reached its peak, so Riddle came to Hayato on his seventeenth birthday and decided that if he couldn't protect him alone no more, it would be safer for Riddle to make a contract with Hayato and make sure that he learnt the skills to fight as an Undertaker.
His former contractor was Roen (the two seems to have an interesting relationship since Riddle commented they know the deepest parts of one another and Roen calls Riddle his and beautiful), the leader of the Arcana. He was also Faust's predesuccessor's secretary and was responsible for killing him after he allowed the Twilight Key to take over him this is probably the cause of why he refuses to get closer to anyone especially Hayato since he is the next King. It is revealed that he was plotting to bring back his former contractor, Sigurd, because it was a request made by Sigurd. He would awaken Sigurd from Hayato and open the Twilight Door. When Sigurd tried to open the door, it failed because Riddle gave him Roen's soul instead of the last fragment of his soul. Riddle puts the last fragment back into Hayato and makes another contract with Hayato. After preparing Funeral March, he talks with Sigurd one last time, stating that Sigurd probably hates him now. Sigurd responded by saying that he could never hate him. Afterwards, Sigurd disappears, and Riddle says that he will never see Hayato again due to the fact that he is an arcana and that he injured Hayato. Hayato says that he will wait for him while Riddle is in prison. After the time-skip, Riddle rereads the latter Hayato sent him long ago again. Later, his time in prison is up and he believes that Hayato probably forgot about him. Then he heard footsteps coming to his cell and assumed that it would be the guards taking him out. However, he heard a familiar voice, and when his cell was opened, it was revealed to be Hayato, who was holding flowers. Hayato states that they finally meet again and smiles at Riddle. Riddle remarks how Hayato tried to get away from him before. Riddle then says my condolences to Hayato.
- "I couldn't let those spirits kill the future King before my very eyes." (to Hayato, about the evil spirits.)"
- "I will play the Funeral March that's right for you."
- "Blue roses are the symbol of impossibility. It is the color of rose that you cannot create, whether naturally or artificially."
- "If you worry about people's pain, you will surely become confused. You have to coldly and cruelly abandon the human heart inside of you. If not, the only thing remaining will be a deep, entwining regret. I couldn't endure that." (to Hayato)
- "Were you jealous?" (to Hayato)