The supporting character's harem is very normal - Chapter 22: My name is Heavenly Rainbow Almighty Emperor Cauldron

Ren Takahashi, a shy, hoodie-wearing tech genius, hides behind the online alias GhostHood — a quiet legend in underground hackathons. Despite appearing average in school, he dreams of becoming a real-life Iron Man — not the hero, but the builder of world-changing tech.Enter Aoi Hoshizaki, a bold, gal-style girl with a love for code, a messy room, and a mysterious spark. When she moves in next door and discovers Ren's secret, their world begins to change — from quiet club meetings to national hackathons, late-night debugging sessions to secret rooftop conversations.What starts as teamwork grows into something deeper, more complicated, and far more electric than either expected. Together, they aim for Japan’s most elite tech university — and face rivalries, rumors, and the whisper of love in every line of code.

She had a request for him and was forced to sign a contract with him.After the contract expired, he actually wanted to discuss renewing it.'I can cook.' One day when she came home, she saw a table full of various delicacies.'I can make money.' In the office, he laid a row of Black Cards in front of her.There was even one night, when she returned home, he calmly looked at her and said, 'I can also...!''......'So that night, someone posted online seeking help: Urgent, waiting online, what to do when entangled with a domineering CEO?

“Is this man not going to divorce me? Why does he still ask me to warm the bed every night?”

A certain man said this was due to the winter being too cold. However, when summer finally arrived, she still needed to warm the bed, thus a certain girl could not take it anymore:

“I want a divorce!”

A certain man only smiled wantonly and said, “Divorce? Sure, as long as you agree to two conditions of mine.”

“What conditions?”

“Either you pamper me or I pamper you, the duration is ten thousand years…..”

- Description from Novelupdates

As the number one pill alchemist of the immortal world, Mu Chen had always believed that it was because he had single-mindedly focused on concocting pills that led to him to neglect disciplining his disciple. Which in turn, caused his disciple to be led astray by the seduction of devil cultivation, leading to the three realms to fall to disaster. After his rebirth, Mu Chen resolved to properly teach his disciple, give him the very best resources, earnestly love him, carry him close to his heart, teach him by way of example, and didn’t let him grow corrupt.

Sure enough, his disciple became more and more “intimate”. Every day his disciple even crawled into his bed, rubbing against his chest and clinging to his thigh. It was just that his expression isn’t exactly quite right……

- Description from novelupdates