Toaru Majutsu no Index - Volume 2, Prologue: The Same Usual Every Day. The_Beginning_of_The_End.

Cheng Yin likes her deskmate Chen Yan for a long time, but she never dared to confess her love for him, and the phrase ‘I like you’ is a secret hidden in her heart, but she can’t help but blurt it out from time to time…
Cheng Yin: “Chen Yan, I’ll whisper something to you.”
Chen Yan always leans over quite cooperatively, “What?”
The words came to her lips, Cheng Yin blushed and changed it into: “Your pants are unzipped.”
Chen Yan: “?”
Later, this kind of useless whispering has become more frequent, and Chen Yan listened again without moving a bit: ” Speak.”
The day of the party, Cheng Yin drink for the first time, Chen Yan became two in front of her eyes, she grabbed the person with both hands, want to try to catch the real Chen Yan, only to have her hand caught, he lowered his head in her ear and said: ” Let me whisper to you.”
Cheng Yin: “…… what?”
Such bad behavior, she thought it was something bad, Cheng Yin checked her pants and made sure the zipper was closed before she lean over.
The man’s breath blew softly in her ear, laced with a bit of the smell of wine.
“I like you.”

- Description from Novelupdates

10 years ago, after “the Gate” that connected the real world with the monster world opened, some of the ordinary, everyday people received the power to hunt monsters within the Gate. They are known as “Hunters”. However, not all Hunters are powerful. My name is Sung Jin-Woo, an E-rank Hunter. I’m someone who has to risk his life in the lowliest of dungeons, the “World’s Weakest”. Having no skills whatsoever to display, I barely earned the required money by fighting in low-leveled dungeons… at least until I found a hidden dungeon with the hardest difficulty within the D-rank dungeons! In the end, as I was accepting death, I suddenly received a strange power, a quest log that only I could see, a secret to leveling up that only I know about! If I trained in accordance with my quests and hunted monsters, my level would rise. Changing from the weakest Hunter to the strongest S-rank Hunter!

Chen Heng is called a pervert.

For killing his sexual partner, the dejected gong forced him to bind with a cheap system.

He has played a series of roles such as: the Holy Mother, a foolish idiot, a wretch, a very perverted and very cruel tyrant… The goal is to get rid of the cheap system, and return to the original world.

Confessions of the small gong:

My lover is a pervert, he is very violent, arrogant, black belly, and vicious.

But I still love him.

I want to break his wings and cut off his limbs.

Capture him, possess him, collect him, and let him be mine.

Small shou: Scram! Don’t talk to me!

Small shou: arrogant, cold, black belly, vicious

Small gong: more arrogant, colder, more black belly, and more vicious

- Description from Novelupdates

After her rebirth, Yun Shifei returned to her fifteen-year-old self, just when she became the true daughter of a wealthy family.The well-behaved and timid Shi Fei only wanted to live her own small life well.Who knew she would get involved with the Great Demon King.In her memory, this big shot was extremely ruthless, squandering the family fortune, watching his brother die coldly, and sending his father to prison.But now, the big shot is quiet, obedient, easy to bully, and loves sticking to her.Yun Shifei's heart softened, and she tried hard to protect him.Yet one day, the little poor thing she sheltered pulled her into his arms to kiss her.She was utterly shocked.He looked innocent and said: 'I heard this is a way to express liking. Don't you like me?'That's what it means, but why does something feel off?!