We see Hiei walking a snowy landscape; a moment later the image shifts into a group of koorime talking around the fire.

"Hina had twins," says one of them.

"One is a boy," says a younger woman named Rui.

"It's a Forbidden Child," announces the Elder.

Hina sheds teargems as she begs, "My son! Please give me back my son!"

"The Forbidden Child must be banished," the Elder replies coldly.

At the edge of an ice cliff, Rui holds a bundle wrapped in ward straps.

"Rui, have no mercy," the Elder commands her.

"Rui, don't do it!" yells Hina. Two other koorime hold her back so she won't interfere.

Rui drops the bundle, which disappears in the mist.

Inside a dark cave, Hiei wakes up. "The same dream again," he thinks.

In Raizen's lands, Yusuke trains with Hokushin and three others. Yusuke insists that they should attack him with all their strength and power.

"If you don't give me your best, what's the point of the practice?" He stares at the tower where Raizen rests. "I won't give up until the old man tells me the truth."

"Such a stubborn kid," Hokushin sighs.

In an insect-shaped fortress, Mukuro asks for a report on Hiei's situation. Kiren says that Hiei has been fighting in the underground for half a year already, and that he might have been killed by the 500 youkais that had been sent there by Mukuro's orders.

"Kiren, how long have you been my second-in-command?" asks Mukuro.

"About 250 years."

"Hn. You should have sent 1000 youkais instead of only 500."

"Why are you so interested in that boy? He's just an ordinary youkai."

Mukuro does not answer.

In the underground, Hiei unleashes the Kokuryuuha, which massacres most of the attacking demons. There are mutilated bodies lying everywhere.

The few remaining youkais, knowing the Kokuryuuha's weakness, wait until Hiei collapses in exhaustion to charge once more. But even worn out from controlling the Black Dragon, Hiei manages to use his formidable speed to kill all the youkais with his katana.

However, sleep eventually wins over him, and another dream takes him back in time.

Rui holds the warded bundle close to her chest while the koorime, standing around the fire, discuss. A female voice says, "The koorime live in a remote country, avoiding the contact with other countries."

"Hina had twins," says an old koorime.

"One is a boy," says Rui.

The koorime are shocked at the news. "What?! A boy!"

"It's a Forbidden Child," announces the Elder.

"Hina kept a secret love affair with a man while the country fell apart for a hundred years."

"What a sick, dirty woman!"

The bodiless voice returns to explain, "The koorime live long lives. During the period the Glacier falls apart, they give birth without anyone's help. The child is part of the mother's body. As long as the koorime don't mate with men, all children will be female."

One of the koorime complains to the Elder, "As soon as she came back to the Glacier, the twins were born. What do you think of that?"

Inside the warded bundle, baby Hiei is attentive to the discussion around him. We hear adult Hiei's voice remembering, "Even as a newborn, I could see and hear. I had enough strength to attack the old women sputtering in my ear."

The scene changes to show Hina on her knees, begging to the Great Elder. "My son! Please give me back my son!"

"Hina, you have disobeyed the laws of our country," says the Elder. "In the past, a Forbidden Child brought the koorime many misfortunes. The girl belongs here, but the boy is impure, can bring only disgrace."

"Then I'll leave the Glacier and raise my son far away from here," Hina cries in despair. "But please give him back to me!"

But the Elder is adamant. "No! The Forbidden Child must be banished."

Now we're taken to the edge of the Glacier, where Rui holds baby Hiei over the abyss. The Elder watches, a few steps behind. Two other koorime hold a crying Hina back.

"There's a serious reason why the koorime live under such rigorous laws in the Glacier," explains the bodiless voice. "If one keeps a secret love affair with a man of another tribe, she'll have a male child, usually evil and cruel. The Koorime who gives birth to a boy — with no exceptions — must die, so she won't influence the others."

"Rui, I know of your close friendship with Hina," says the Elder. "But show no pity. You know that many koorime died because of a Forbidden Child. Have no mercy."

Rui gives Hiei a hiruiseki attached to a necklace. "Please, come back alive," she whispers at the baby. "And the first thing I want you to do when you return is kill me. That's the only way I can make up for Hina's death."

"What are you waiting for, Rui?" asks the Elder. "Have no mercy!"

Rui drops Hiei in the abyss.

"Don't do it!" Hina cries.

Again we hear adult Hiei's voice. "I was strong enough to survive. And I cherished this goal I had since I was born: to kill all the koorime."

Hiei wakes up. "The same dream again."

A door opens and Mukuro comes in. "Ah, finally awake. The attack of hundreds of youkais was not enough to bring you down. Why don't you join me? Your powers have grown to the highest levels in only six months. You are a formidable warrior."

"The stronger I become, the less I care, idiot," says Hiei. "What kind of youkai are you? What does your face look like?"

"Would you like to see it?" asks Mukuro. "Very well, I'll bring you a warrior as strong as you are. I will show you my body if you manage to defeat him."

"So all I have to do is win?"

"Correct. Besides my subordinates, I have 77 rigorously selected generals that are the closest to me. There's no reason why there should be 77; I just happen to like that number. I'll bring you one of them. If you defeat him, I'm willing to show you my body and name you my general."

"I want absolutely nothing," Hiei snaps. "I don't need titles."

"Oh, don't say that. It'll only benefit you. It'll make it easier to receive favors from others so you can find what you've been looking for."

Hiei's eyes widen in surprise.

Mukuro leaves, promising to return in five minutes.

Annoyed, Hiei vents his anger on a large statue of a hooded woman, cutting it in half with his katana. The gleam of the hiruiseki hanging from his neck summons another memory.

The Tokubetsu Bouetai are opening the tunnel so Yusuke can go to Makai. A little away from where their friends stand and wait, Yukina and Hiei have a private conversation.

"Please, take this with you," says Yukina, handing Hiei a necklace with a hiruiseki. "Do you really intend to go to Makai? Then take it with you, it's a memento from my mother. When a Koorime has a baby, she cries a tear that turns into a gem, which is granted to the child. Mother shed two hiruiseki. One was granted to me, and the other to my brother."

Yukina reveals that she kept Tarukane from taking that hiruiseki from her by swallowing it and hiding it in her stomach.

"Why are you giving it to me?" asks Hiei.

"Rui secretly told me that my brother was protected by an energy of fire, a sort of spell that involved him, guarding his body."

"Rui?"

"Yes, she was Mother's friend."

Hiei recognizes the woman as the one who dropped him in the abyss.

Yukina inadvertently addresses Hiei by a Japanese word that means 'my older brother'. At Hiei's surprise, she instantly apologizes for her 'mistake'. "I'm sorry... I think my brother must be just like you." She gives him her hiruiseki. "If you find my brother, please give him this, and tell him I'm going to stay here."

Hiei examines the hiruiseki. "He was thrown in the abyss. He probably didn't survive the fall."

Yukina smiles confidently. "I think he did." She says that Rui once told her that her brother, even as a baby, seemed to understand everything people said around him. Rui was sure that he would come back to seek vengeance.

"And I believe it," says Yukina. "I'd rather die than live forever with... with a cold heart... and in the Glacier."

"Hn. And is that why you left your country?" asks Hiei. "So it was all a lie when you said that you were allowed to leave the Glacier to look for your brother? Have more confidence, girl. If you want to destroy yourself, do it on your own. Don't count on the help of a brother that might very well be dead by now."

Yukina's eyes widen sadly, as if she's gonna cry. Hiei looks away with another "Hn."

"You're right. You're absolutely right," Yukina smiles joyfully. "My brother would have told me the same thing."

The memory is gone before the upper half of the statue falls on the ground.

"My hiruiseki is protected by my ki," Hiei muses. "Then why can't my Jagan find it? Maybe someone is hiding it inside their stomach too?"

Mukuro comes back, along with one of the generals.

Hiei recognizes him. "You are Shigure, the Makai surgeon. When did you decide to join Mukuro?"

"Right after your surgery," answers Shigure.

"So you know each other?" asks Mukuro.

"Doctor/patient relations," says Shigure. "Also, I taught him some of my art as a swordsman, and he perfected that art without any tutoring."

Shigure admits his surprise at sensing Hiei's current ki level, since the surgery to implant the Jagan depletes the energy of the patient. Then he notices Hiei's necklace. "So you have found the hiruiseki you were looking for."

"This isn't mine!" Hiei snaps defensively, tucking the necklace under his tank top.

"Ah, so it's your sister's. Either way, you have found one of the things you were searching."

"Tell me this mysterious story," Mukuro commands.

"Hiei had the Jagan implanted so he could look for two things," Shigure reveals. "One was the Glacier where his sister lived. The other was the hiruiseki conceived for him by his mother. I only agreed to perform the surgery after a deep examination of his life. My remuneration was the promise that he would never reveal his identity to his sister." He points his circular sword to Hiei. "If you manage to defeat me now, I will give you back the remuneration."

"I told you before the surgery that I will never tell her who I am," Hiei insists.

"Ah, but a heart can change..."

"Enough with the memories!" says Mukuro. "Let's settle this. It will be a combat to death."

Hiei unsheathes his katana. Shigure prepares to strike.

"Begin," Mukuro commands.