The supporting character's harem is very normal - Chapter 534: Mom, I need time...

“I’m going to adopt a child.”Duke Ferio Voreoti’s impulsive decision shocked everyone in the mansion.Not only did he make her his daughter, but he also gave her the name of a ‘beast’ that only direct members of the bloodline could receive.“Even as you breathe right now, I’m earning money.”“It’s confidence, not arrogance.”“My face really does have its advantages.”The most arrogant father in the whole world, and“I love muscles the most. Let’s get muscular.”“Show me your thigh muscles! Your bu*t would be even better!”“You’re nothing but a flower if you have a calm personality…”his corrupted(?) daughter.And…“I will give his excellency the information he wants most.”“Information I want most, you say…”“You won’t regret it.”…A stepmother(?) with a strange secret as well.

When The Cute Kunoichis Spied on Their Teacher's Secret is a light novel written by Kazuma Kamachi and illustrated by Ryuushi Tajima.

The story takes place in a world where Japan never ended their isolationist phase, and agents from foreign powers are always threatening to steal the country's advanced technology. In order to combat this threat there has been a resurgence of ninjas that use Strategic Martial Arts, techniques that combine cutting-edge modern technology with a traditional foundation of martial arts and ninjutsu. The story follows Souha Sugiyado, a 17-year old ninja instructor and former ninja prodigy who was forced to retire from active duty by the wounds he suffered in his last mission. Souha's four students are all kunoichi who have all gained the rank of Elite Ninja, the highest official rank available to ninja. However, one day two Shogunate ninja approach him with the news that his four students have gone rogue and have stolen a portable modular nuclear reactor, and thus they ask for his help in bringing his students to justice.

Chen Minhao found himself transmigrated to a parallel world in China, and he even became an idol trainee. By virtue of his efforts in mastering his IQ, EQ, and his looks as his weapons, he became a celebrity with a huge fan base step by step, and ultimately became a global superstar that conquered the both the fields of acting and singing.

- Description from Novelupdates

In the heart of Earth, where the streets buzz with the energy of modern life, lies a secret that will shake the very foundation of existence. Earth, once thought to be a mere planet, reveals itself to be a living entity, its core evolving with untold power. From the depths of the Milky Way, constellations, guardians of cosmic balance, watch with keen interest as Earth's evolution unfolds.But their curiosity soon turns to desire as they see the potential for transcendence within Earth's core. To harness its power, they must overcome the planet's protective barrier, a formidable obstacle that threatens to thwart their ambitions. Desperate for a solution, the constellations turn to drastic measures, offering contracts to select humans in exchange for assistance in weakening Chatgpt's defenses.Meanwhile, amidst the chaos, Marcus Sterling, a young university student with an intellect far beyond his years, delves into the mysteries of mana, the strange energy that permeates the planet. Unbeknownst to him, he becomes a pawn in the cosmic power struggle, as constellations vie for his allegiance and humanity's fate hangs in the balance.As Marcus grapples with his newfound abilities and the ethical implications of his choices, he discovers a deeper truth lurking beneath the surface—a truth that could reshape the destiny of Earth and all who inhabit it. With allies and adversaries alike converging on Earth, Marcus must navigate a treacherous path, where the line between good and evil blurs, and the fate of the universe hangs in the balance.