The supporting character's harem is very normal - Chapter 444 Lathel vs. Demon Lord

In a romance novel called “The Secret Lovers of the Academy” the male lead would often torment his fiancée–but wait, why did she cross into this world to become his fiancée, the villainess, instead of the heroine?

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.

As a useless spoiled wild child, Bai YiHan finally brought about the end of his family, chased away the one he loved and caused his own death. After rebirth, he decides to cleanse himself and work hard at being a good child. But a lot of things don’t seem to be as he expected…

Bai Pa + Bai Ma: My son’s so obedient. Someone must be bullying him. This cannot be forgiven!

Bai Big Bro + Bai Big Sis: If my little brother’s sensibility comes from his suffering, then I’d rather he be a spoiled brat forever!

Mu JingYuan: If HanHan hits you, you must accept it. Yet you dodged…The wind’s changing. Someone should be bankrupt to make HanHan smile.

Bai YiHan: …I was so wild in my past life. Your involvement are undeniable!

This story is speculative, speculative, speculative. Important matters must be said thrice. Everything is about speculative time-traveling.

- Description from Novelupdates

It was in the middle of the night that the woman who would be the Duchess came to see me.

She said my father and mother died, and my kind uncle became king.

She said it’s not worth it for me, the crown prince, to be living in hiding, too.

“A while ago, Your Highness had been hiding from me. With all due respect, is that for the sake of survival? Just because your parents died doesn’t mean you have no reason to survive. Actually, that fact alone made it all the more reason why you should live. If you die now…”

If I died now?

When I asked her while looking at her eyes, the woman eventually brought out the harsh truth with empathetic eyes.

“It’s like a dog’s death.”

“That’s rude….”

It’s been a long time since I said that. In a short while, he has been treated as a madman and beaten to death just by saying similar things. She loosened her arms that held me and I suddenly stiffened up due to it. Because I thought she might have loosened her arm to hit me. But she didn’t.

She knelt down with one knee in front of me, just like a knight.

“Hastred’s Sarian raised her salutations. May you accept it gladly.”

My first knight is beautiful and kind.

“Are you on my side?”

“Yes, Your Highness.”

It was all a lie.