Who Wrote The Light Novel Promise The Book?

When Mizuko slipped into the other world, she landed in the arms of a mischievous demon prince, Kenshi. New to the world, she didn't know he was a demon as he looked to her like he was a decent person. Because Kenshi helped her first, Mizuko decided to ask him for help in finding a way home while she fulfills the dead mage's request in relaying the message to the King. But no demon in Souzou helps unless they get something in exchange. A promise, it is what Kenshi wants the most.

A world where magic exists and they call them promises. A girl named Eileen will enter this strange school that will lead her to something she didn’t expect to know. Entering this world will make her life turn upside down. Figuring things out with her own and having people that have magics with them that will help to know why she’s there in the first place. Looking for answers and solving the mystery of this world. She enters the school and meets a girl named Tracey where she finds out about magic but strangely she encounters an incident. An incident that will make everything difficult for her because things are getting started. Encounters someone,an evil person, that wants power and starts to make troubles that are dangerous for them. As the protagonists join forces to stop her but conflicts occur as they go deeper about the secrets of the school.

Born with angelic blood, Lixue has lived her entire life bound to a prophecy she never chose. Raised in the countryside among a family who shared her celestial heritage, she was sent to Heaven at the age of seven to serve the Father and awaken the powers hidden within her soul. But a single night of tragedy shattered her peaceful life—demons invaded their ancestral mansion, and in the battle that followed, Lixue lost both her mother and her brother. From that moment on, her heart closed itself to the mortal world. Haunted by loss and unable to accept death, Lixue disappears into the Philippines, working as a secret agent for her godfather’s underground organization. Her latest mission seems simple: protect Shuji Liao, a world-renowned model, from an unknown stalker. To stay close, she hides her true identity and lives under the same roof as Shuji and his father. But as Lixue investigates, she uncovers a far darker truth—Shuji’s family is entangled in a powerful criminal syndicate that threatens both the mortal and supernatural realms. Shuji, raised between two countries and burdened by a fractured family, finds his once-stable life unraveling. A mysterious incident alters his heart, pulling him away from his girlfriend and toward the woman sworn only to protect him. What begins as duty slowly turns into forbidden love. Unbeknownst to Shuji, a single kiss seals their fate. The prophecy awakens, revealing its cruel demand: Lixue must love Shuji and bear a child destined to save the world from demons, devils, and ancient evils that walk the Earth. But salvation always comes at a price. After their child is born, Lixue vanishes—erased like a dream at dawn—leaving behind a son, a broken lover, and a world saved by a sacrifice no one will ever forget.

The Demon King’s Bride The entire kingdom fears him. With white hair, piercing blue eyes, and a heart sealed by cruelty, King Edrion is known as the Demon King—a ruler who accepts betrothed brides… only to turn them into concubines and discard them without mercy. When a young noble lady is promised to the king, her fate seems sealed. But she refuses to give up her freedom—or the man she secretly loves: a guard from her own household. Desperate, they devise an unthinkable plan—to have a poor girl, identical to the noble, take her place as the royal bride. The girl agrees to assume a life that is not hers, believing she will become nothing more than another forgotten concubine in the shadow of the throne. What no one expected… is that the king would choose her. Now destined to become queen to the most feared man in the kingdom, trapped in a lie that could cost her life, she must survive the court, a forbidden desire, and a king who was never meant to look at her the way he does. Because the Demon King does not love. But when he chooses… he neither forgives nor lets go.

Serra is a normal senior high school student who works really hard every night and weekend to pay off her parents' debts from loan sharks. But when she couldn't keep up with payments anymore, she decided to end her life. Surprisingly, she woke up in a different light-- in another world. What's more shocking was when she is addressed by one of the people as the demon king's bride.

When Lizzy was thrown out onto the street by her ex-fiancé upon discovering him being unfaithful, she swore never to fall in love again. That's why when Greed barged into her life in the worst possible way and, after several unpleasant issues, offered her a contract for herself and her unborn baby, it seemed like a promising opportunity. Now, she is the fiancée of a wealthy mafioso and CEO who eagerly seeks to take control of everything after the marriage and the birth of their child. After that, Lizzy and Greed will be able to divorce, and each can enjoy a peaceful life separately. However, the unexpected appearance of the true father of her child and Greed's genuine fiancée triggers a series of tumultuous events. What starts as a relationship of hatred and convenience through a contract ends up becoming true love.