Seiya woke up feeling incredibly heavy.
He said that and opened his eyes, there he saw a young girl with blue hair.
Yua is younger than Seiya, but the girl in front of him is even younger than her.
She was around ten years old or so, and this cute little girl was currently sitting on Seiya in her birth clothes.
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The blue-haired naked little girl happily hugged Seiya while calling his name.
Seiya answered reflexively, he had no idea who this little girl was.
When Seiya asked the name of a naked little girl, she answered with a sullen face.
「Ehh……Who are you?」
「Did you forget? It’s me, Lily!」
「As I said, who are you?」
Seiya couldn’t recall such a name.
In the first place, If he ever met such a beautiful little girl, he would have remembered. She looked too cute to forget about her.
「Mu…Lily is Lily the Undine. I was fighting with you just a while ago! Did you forget already?」
Seiya became speechless at her answer.
Indeed, if you look closely, you could find Undine’s features. But why did she become so familiar with him all of the sudden?
Besides, Undine should have been erased by Seiya.
「I see … … you are definitely Undine. So, why are you still alive? And what do you want? We tried to kill each other just a few moments before」
「Mu~ I am not “you” or Undine! I’m Lily! Lily! 」
Apparently Lily wanted him to call her by her name. Seiya thought that at this rate the conversation won’t proceed, so he agreed.
「Oh, I got it. So, Lily, what does this mean? What is your goal?」
「Mm, you see, Lily wants to make a contract with Seiya! I promised in the beginning, that if you can defeat me, we will sign a contract!」
「Contract? Perhaps you should cover yourself first……」
Seiya lowers his sight to the ground, looking troubled.
It is troublesome in a lot of meanings, depressingly thought Seiya. At this time, he received a big shock.
「Allow me to explain about that」
Lily’s voice suddenly changed and Seiya raised his face again.
Then there was not Lily, but the previously destroyed by Seiya, Undine.
「Why are you here?」
「It’s not “you”, Seiya-kun. Lily!」
「So you and the little girl are the same?」
「Kind of, the explanation is bothersome, so let’s finish the contract first」
「Okay, but find some clothes first, please」
Said Seiya, while avoiding her with his eyes.
She was stark naked, just like Lily before her.
Lily was a little girl, but Undine in front of him is an adult, the places that should protrude are properly protruding, Seiya couldn’t find a safe place to look.
「Oh, am I not to your liking?」
「Please wear something, or I won’t listen to you」
Undine answered in a playful tone and gestured with her finger. Then, the water gathered around her, and in a blink of an eye, the clothes were formed.
Nodding, Seiya requested for an explanation about the previously mentioned contract.
「Hey, I promised before the fight. If I lose, I will sign a contract」
「You don’t really need to sign a contract. We just want to pass through the Great Dalis Canyon」
That is what Lily said before the fight. If she loses, she will sign a contract.
But it’s not like Seiya particularly wants to do it. He would be content to just leave this place.
But it was more serious than Seiya thought.
「That’s no good」
「What do you mean?」
「If I do not sign a contract with Seiya-kun, I, no, we will disappear.
So we want to sign a contract with Seiya for the sake of survival.
I know that we just tried to kill each other. But please. Save us, Seiya-kun」
「I don’t really understand yet. Explain properly」
Seiya asked Lily, who lowered her head. He had only read books on fairies and spirits from the library and didn’t know anything about contracts.
「First of all, fairies and spirits need a source of mana to live in this world.
There are different sources of mana, but what they have in common is that we can’t live without them.
For example, in my case, the water in the lake was my source of power」
「I see, so how is that related to the contract?」
Seiya couldn’t grasp the meaning of the contract.
「That means that the magician can become a source of our mana. In return for mana, we will lend the magician our power.
There are two kinds of contracts. First is a complete contract with full mana supply, the second is a partial contract, where in return for prolonging our lives we lend a part of our power to the magician.
That’s why we would like to ask you for a complete contract」
Seiya understood that she was serious, but he couldn’t agree without fully understanding the contract.
「So what’s the catch?」
「The disadvantage is that the exchange of mana is necessary regularly. We will receive mana from Seiya-kun and Seiya-kun will receive mana from us. Manipulating enormous amount of mana is dangerous for most of the magicians, which makes complete contract impossible.
But since Seiya-kun has both『rising』of the light attribute and『annihilation』of the darkness attribute, Seiya-kun is the only person we know, who can sustain a complete contract.
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If you ask for other disadvantages, it is the fact that we will have to stay close to you most of the time」
Said Lily with a passionate voice, but Seiya wasn’t moved.
「I understood everything. But please excuse me from your company」
「Seiya-kun is so heartless. Also, it’s Lily! 」
Apparently, the adult version of Lily wants to be called by her name too.
「If Seiya-kun wants something, big sister will listen to anything~」
Lily suddenly embraced Seiya and pressed her plentiful breasts against him, creating an erotic atmosphere.
Because Seiya is also a man, a certain part of his body responds without permission. Lily, who noticed that, whispered in his ears.
「If you make a contract with us, you can do what you want. Even lewd things」
「Uh…by the way, why do you want the contract so much? You can still replenish mana here, right? 」
Trying to distract himself, he switched the topic.
「Certainly, it will take time, but we can still regain our power here. But we are tired of it. We are tired of this lake, as well as this giant canyon. We want to see the outside world.
But we are fairies, we can’t leave. Staying in the same place is incredibly boring. So please, take us to the outside world」
Listening to Lily’s story, he saw a glimpse of himself somewhere.
He was the worst magician of the academy, he was without ability and family, however big was his desire to change, he didn’t have the power to achieve it, without changing, he just continued to exist in the academy environment.
That was the same for Lily. They can’t leave this lake. Even if they wish to, they have to stay here forever if they want to stay alive.
While Seiya was thinking, Lily continued.
「Besides, if you make a contract with me, you will be the biggest winner」
「What do you mean?」
「You still can’t control that dark power, right?」
「How do you……」
She was talking about the power that defeated her.
At first, Seiya just wanted to help Yua, but later he found a pleasure in destruction. Although he was conscious, he wasn’t in control of his own body from the moment of defeating the sea god Neptune.
He felt like he was just an observer.
「That power was dangerous. If we are to explain, you have a second personality deep inside of your mind. Although Seiya-kun controls the body right now, you can never know when the situation will be reversed.
You are similar to us; you can’t do anything about it. But if you make a contract with us, the number of personalities will change to two vs one, like that you can restrain the other personality」
Seiya found Lily’s words reasonable but still couldn’t trust her just yet.
「But can I consider you an ally?」
「Well, if I cooperate with another personality, Seiya-kun will definitely lose control of his body. But I won’t betray you, my life was almost extinguished by your hands, so I want to use it for your sake. It’s true, believe me」
He felt from her eyes that her words were real. Probably she will never betray him. And if it is so, this contract if a great plus. 
Without strength, he can’t protect Yua, but his power could destroy him someday.
If he would be able to wield this power as he wishes, it will be a great help to him.
「I understand, let’s make a contract」
「Is it true? Thank you Seiya-kun, I’m sorry for what I did to the two of you」
「You did it to protect yourself, can’t help it, right?」
「Come to think of it, how do you make a contract?」
「Ask the other girl. Apparently, I’m out of time」
In the next moment, Lily disappeared and little Lily appeared instead.
They seem to really share one body.
「Oh, so how do you make a contract?」
Seiya was embraced by a beautiful little girl and made a troubled face. He wanted to make a contract as soon as possible.
Although he was currently safe, he was anxious that he could be deprived of his body at any moment, so he wanted to make a contract with haste.
「Un, you see～ Close your eyes and let your mana flow outside your body. Lily will do the rest!」
As he was told, he closed his eyes and slowly released his mana outside the body. Wrapped in yellow and purple mana, Seiya thought.
（With this I will be able to protect Yua）
Seiya felt that his mana started moving without his will. Most likely, Lily is manipulating his mana.
（I won’t lose her anymore……mm? ）
Seiya felt an unusual soft sensation on his lips. It was a very comfortable and somewhat sweet feeling.
But at this time.
Seiya hurriedly opened his eyes and saw Yua, who looked incredibly sulky for some reason.