Can you recommend some serious novels or similar works like "Book of the Girl's Contract" with a theme of freat/zero?

I recommend "Seal of Youth" to you. This romantic youth novel tells the story of a beautiful and affectionate young girl waiting for love. In this novel that was similar to a girl's contract, there was also a deep emotional entanglement between the two protagonists. I hope you like this fairy's recommendation. Muah ~😗

I recommend 'The Manager of the Other World' to you. Although it was not exactly the same, it was still a contract novel. The protagonist traveled from the blue planet to a world full of swords and magic, signed a contract with a talented young magus, and began a series of adventures across different worlds. I hope you like this novel.

😋I recommend the following novels similar to "Teenage Contract" to you: "Overbearing Husband: Please Be Gentle,""Proof of Contract,""Contract Demon Concubine," and "Special Pet for Dumb Sweetheart." These novels were of different types, but they all had contract settings, including modern romance, fantasy, sword and magic, and so on. I hope you like this fairy's recommendation. Muah ~😗

😋I recommend the following two novels to you: "A Comic Girl's Journey to a Different World" was similar to "The Great Summoning of Girls." It was also a girl who accidentally entered the 2D world and started a wonderful adventure. In this parallel world, she would meet all kinds of 2D characters, explore mysterious worlds, and live a colorful life. "I'm a Dragon, and I've just become a magical girl": Although it's not exactly the same as "Book of the Girl's Contract", it's still a light novel, a derivative of a doujinshi novel. It also has a super attractive fantasy plot and magical elements. The main character was a girl who had transmigrated to the dragon race and became a cute magical girl. She was going to fight a group of demons and embark on an adventure. I hope you like this fairy's recommendation. Muah ~😗

I recommend " I Have a Magic Book " to you. It's similar to " The Book of a Girl's Contract ". The main character obtains a mysterious book and needs to sign a contract to solve the problem. This novel also added elements such as a game store and a lucky draw treasure chest. It was an original fantasy novel and was very worth reading. I hope you like my recommendation.

I recommend the following novels to you: "Transform into an otaku girl": The protagonist turns into an otaku girl, and the plot is full of funny and cute scenes. "Black Basket: Ziyuankun is a Little Cute": A Doujinshi spin-off novel. The story of the main character Natsukawa Kazuo and the young man sitting in front of and behind her, sweet and cute. "My Scamming Brother": A romantic youth novel. The protagonist, tall, rich, and handsome, became a girl's "hired boyfriend." It was a sweet and painful growing up story. I hope you like this fairy's recommendation. Muah ~😗

, I recommend you to read "The Platycorus Flower Blooms Again". This is a light novel, a doujinshi derivative novel. Similar to "The Book of the Girl's Contract," it is a doujinshi manga novel. The main story was about the protagonist who had gone through many vicissitudes. After breaking free from the prison, she entered another prison when she was reborn. Then, her story unfolded. I hope you like my recommendation. Muah ~

😋I recommend the following comics to you: 1. "Offering Heroic Spirits to a Bad World" was a light novel similar to "Book of the Girl's Contract." The main character held the Book of Heroic Spirits and traveled through various worlds. 2. "Comic: The Descent of the Contract God". The real name of the book was "Adventures in the Grass Hat Group". The main character adventured in various worlds, met various characters, and carried out various missions. 3. In "Comic: 2D Please Answer," the main character Lin Ya traveled through various worlds to carry out missions, covering many characters and worlds. The above is my personal recommendation. I sincerely hope you like it ~

One similar light novel could be 'Sword Art Online'. It also has elements of a fictional world with unique relationships and adventures. Another is 'Overlord', which features a powerful main character in a different kind of fantasy setting. And 'Re:Zero − Starting Life in Another World' is also somewhat alike as it involves a character in a strange world facing various challenges.

😋I recommend "The Manager of the Other World" to you. The main character of this fantasy epic fantasy novel is also a transmigrator. He signs an agent contract with a talented young magus and embarks on the unknown road of adventurers together. The main character is a kind-hearted young man, and he fits the requirements of the "Book of Maiden's Contract". I hope you like my recommendation, Mwah ~😗