If you're looking for manga similar to The Princess of Convenient Plot Devices (Light Novel), you might like these titles.
"I am the only one allowed to leave you with scars." Waking up in a Chinese-inspired alternate world?! One day, Miyuki suddenly finds herself reincarnated as the beloved heroine of a novel she adored in life. As Shinsetsu, she marries Rensei, a king from a foreign land, but she is immediately told that an heir is needed, leaving her no time to settle in! The king's love grows stronger day by day, and with sweet, straightforward words, he melts her heart. At the same time, her innocent body slowly takes on a more alluring hue...
I recalled memories of my past life after Grandfather told me my engagement was annulled. At the same time, I realized this world was the same world as in my favorite shoujo manga. The villainess who exhausted every method possible to bully the heroine… I reincarnated as that villainess’ chubby follower. I shook upon remembering the future lined up for her. When the villainess’ evil deeds came to light, she pinned all her crimes on Britney. I was a character that gets executed.
I became the main character who beats around the bush in an angsty romance fantasy novel. The role of the heroine who gets thrown by the male lead and is ignored by her best friend. It can’t go this way! I have to change the original route by all means. “Please employ me as your support.” To survive, I decided to stick to the antagonist, the crown prince, of the original plot. However, this man is in no way going as planned. To add, even a weird rumor is going around. That I and Palus are lovers, with plans of a wedding ahead.
After realizing she's inside her favorite novel, Ellenfiela uses her "prophetic powers," a.k.a. her knowledge of the story, to make money! This catches the eye of the imperial palace, and she's recruited to help the emperor, who has an unusual problem. But this wasn't in the original novel, was it?!
Geumja Kim is the biggest (and only) fan of Kyle du Vilteon, a side character in the fantasy novel King Maker. Her never-ending search for Kyle content is forever changed when she dies while rereading the book… and somehow awakens in Kyle’s bedroom to a new life within the novel’s pages! She is then shocked to learn that Kyle can also hear her thoughts—luckily, only if she thinks of his name. Still, there’s no time for this fangirl to daydream because Kyle is doomed to die. Can she save the apple of her eye... and in the process, become his?
I had possessed a character inside of a book. Into the book where I pushed the ‘ Female Lead x Emperor’ pairing. The day I shed tears over the two characters that don’t end up together, I was sent here to experience the whole story. “Stand in line to hear my prophecy!” I began to make money from the contents of the book. Guys! You don’t have to end up together, but you have a lot of money but I don’t. So after three months, I am brought to the Imperial City by the name of the Emperor after spending money in prophecy, following the original truth, the law of Man-go, the golden almighty. Then I met the Emperor for the first time– “You know everything.” “Yes, I know a lot.” “Yes, then can you tell me when I’ll come back to my original state.” Finally, the emperor appeared beyond the white cloth was a four-year-old kid. …why is he so young?
After awakening in a webnovel as Princess Clara, this former office worker isn’t getting the royal treatment. As the shy sister of the tyrannical King Bastian, she’s immediately faced with disdain and so much drama! Plus her character's destined to be seduced by his latest hostage, Crown Prince Daniel, accused of betrayal, and executed. But Clara’s got a backbone and a plan to win over her brother. She’s ready to take control, slap some sense into meddling nobles and servants, and resist the charms of her handsome (really handsome) charge!
Transmigration is easy. Step one: Figure out which novel you’re in. Step two: Expertly navigate the complex web of political relationships, ensnaring the heart of your male lead. Step three: Live happily ever after. Or that’s how it’s supposed to go, unless you’re avid-reader Elena Sevess and can’t get past step one! Unless she can figure out where this story is going, Elena is in a world of trouble... or is it the world that’s in trouble because of her?
I’ve transmigrated into the body of the wife of the mad villain emperor in an angsty novel! How will I escape? By running away quietly when the saintess he’ll become obsessed with appears. This love-blind emperor won’t even remember that I exist once he lays eyes on the saintess! I really didn’t do anything. All I did was lay as low as I could so that I wouldn’t get on my crazy husband’s nerves…. But the villain emperor has asked me to return to the palace with him, and not the saintess. But she’s already here! Why are you obessessing over me?