Is 'One Piece With Sign-In System' A Fanfiction Or Original Novel?

I woke up inside a novel, and not even as an important character. I became a pretty background extra in a smut novel. My brother, however, was the only normal person in the entire story. His character setting was the one man the soft, delicate heroine could never win over. He was the cold, unattainable Prince Charming she could never conquer. When the heroine cried and confessed her love, he was studying. When she offered him her whole heart and body, he was busy starting a company. When she spiraled into scandals and nightlife, he was already a billionaire, calm and untouchable. I thought he would live a quiet, ascetic life forever. Until one night, I walked in on him at midnight… holding a piece of clothing I recognized all too well, murmuring a name over and over, a name so familiar that my scalp tingled.

Awakening to a bewildering and astonishing reality, Seraphina found herself in an extraordinary situation: she had transmigrated into her own novel, stepping into the shoes of a character she had meticulously crafted. The male lead in her story was notoriously elusive, challenging to approach, and the master of a harem. Seraphina, now Zephyrine Everlynn, unexpectedly found herself among the women in his harem. It was utterly absurd! Promptly leaving the harem, Seraphina used her knowledge to help others win the male lead's heart, all for the right price. But why did the male lead continuously find his way back to her?

On the Lunaris Festival, the palace banquet glittered with candlelight. It lasted until the Crown Prince rose and dismissed every consort of his for the sake of his first love, the woman he had never stopped idolizing. Everyone else accepted the gold coins from the prince and returned home for reunions. I had nowhere to go. I found a rope and hanged myself at the gate of the Withered Court. I had been reborn into this world and spent 21 years locked in the System's mission. It demanded that I court four designated male leads and earn absolute affection from at least one of them. I failed every route. The final path collapsed in my hands. The System offered one last mercy. If this body died, I could return home and reunite with my family. As my consciousness slipped away, I thought I heard someone scream my name, as if the world itself were breaking.

A thirty-year-old office lady, who got into an accident and is now trapped inside a novel series she loves. She was reincarnated into one of the side character extras of the story and meets in person the tyrant magician, the playboy prince, and the clueless female lead of the story.

The day I was about to quit the game, countless floating comments suddenly appeared before my eyes. [Finally! The villainess is quitting!] [Now Janet Cole doesn’t have to worry about getting exposed for using her account to flirt online.] [The heroine is so smart–she always uses voice chat in-game. The villainess has no idea.] [Janet is living the dream–using her max-level account to juggle five top-tier players at once!] [At 2 PM today, she’s meeting her 'No.1 catch'–the cold, untouchable campus heartthrob Cedric Barnes!] [Assassin god tomorrow, rich scion the day after… her time management is insane!] The Janet they were talking about… was the fake heiress who had taken my place in my own family. She had been impersonating me–using my account to flirt with five elite players at once? Then more comments appeared… [Why hasn’t the villainess left yet? The male lead is already waiting.] [This is the first sweet date between the leads–can’t wait!] I turned to look at Janet, touching up her makeup in front of the mirror–and suddenly, it all clicked. The 'villainess' they were talking about… was me. So the real heiress–me–was nothing more than a disposable side character, a stepping stone for the fake one? A faint smile curled on my lips. If she could impersonate me online and play the field, then me showing up in person and stealing everything... wouldn't be too much, right?

After transmigrating into a novel, I realized the heroine and I had the exact same name. Naturally, I thought I had transmigrated into the female lead. So I marched straight to the man who was still a broke nobody at the time, threw all caution to the wind, and pounced on him like I had plot armor protecting me. He even glared at me with red eyes and told me he hated me. I honestly thought he was just into the whole push-and-pull thing. Everything shattered when the real heroine showed up and I finally understood one thing. He actually hated me. Heartbroken, I packed my bags and got ready to disappear. The next second, he pinned me against the wall. "Where are you going? Already bored of me, sweetheart?"