[POV: Ritsuka_Male]
Currently Ritsuka is in his room after he finished all the current Singularities: Cosmos in the Lostbelt, before that Ritsuka fainted from exhaustion so Mash servant Ritsuka carried him up to his room safely 3-4 hours Ritsuka woke up from fainting. He pondered for a moment and in his mind wished that Cosmos in the Lostbelt Singularity: Nahui Mictlan was the final singularity, and that they could finally return to the real time. Just as Ritsuka was about to get out of bed, suddenly a summoning magic circle appeared under his feet and the circle glowed brighter and then disappeared along with Ritsuka.
[POV: Ritsuka_Female]
Ritsuka, Mash, and Artoria Caster managed to protect this world from being destroyed. With this the mission of the Singularity Cosmos in the Lostbelt: Avalon le Fae has been completed. After Ritsuka and Mash said parting words and congratulations to Artoria Caster who had become the new King of this world. After that Ritsuka walked to his room suddenly a summoning circle appeared under his feet. The circle shone brightly making Ritsuka's eyes dazzle and then disappeared together with Ritsuka.
[POV:Male & Female]
Two magic circles began to appear in the large space the two magic circles were shining very brightly and slowly at the same time there were two people who were in the large space the two people looked around before turning around and looking at each other, each of them both thought the same thing "how come I can be here and ready for this girl in front of me?, and she is quite cute." thought (Ritsuka Male), "why can I be here and ready for this man? But if you look at him he's pretty handsome too." she thought (Ritsuka Female) then Gaia spoke.
Gaia: Nice to meet you two Fujimaru Ritsuka the last master of Chaldea.
Male: How do you know my name?
Female: How do you know my name?
Male: Uh...
Female: Uh...
Male: Are you Ritsuka???
Female: You too Ritsuka???
Male & Female: IMPOSSIBLE!!!!!!!!
Female: HOW COULD THIS HAPPEN.....!!
Male: Calm yourself down.
Female: HOW CAN I BE CALM AT A TIME LIKE THIS!!!
Male: About if what he said is true, which means you and I are the same Fujimaru Ritsuka but different gender and nature with me right Gaia?
Gaia: You're right Fujimaru Ritsuka. you and that girl are the same person.
Female: Like that Mmm..., okay I can believe it especially since I often switch Singularity from one to another.
Gaia: I'll get straight to the point, I was asked to send two people to one of those worlds where the age of the gods never ends.
R. Female: What the hell are we both only human while in that world there are creatures that can kill us.
R. Male: I'm sorry but what the Female version of me said is true, we are just ordinary humans, we are servants or hero spirits.
Gaia: That's why I'll increase your magic circuit count and give you a servant card as a gift.
R. Female: What's the servant card I just heard about?
R. Male: Didn't Da Vinci-san say that every world has various ways to make contracts with servants.
Gaia: You're right and one of them is to seal the fighting spirit of the servant and how to install which means uniting oneself with the servant.
R. Male: Uniting oneself with a servant surely requires compatibility and there must be risks? Am I right, Gaia.
Gaia: Indeed, it takes a high compatibility to be able to use the power of a servant and if it doesn't match the possibility that the one using the servant card will die. But don't worry, I will choose a servant card that suits both of you.
R. Female: But why us? It's not easier if you send a grand servant right?
R.Male: What he said is true, can we know the reason?
Gaia: That's because the one asking me doesn't really trust me. So he himself chose you, and gave you strength, of course you can call servants because you are both masters, but I limit it to 3 servants for 1 person.
R.Male: So because there are 2 of us we can only summon 6 servants I think that's more than enough and added with servant cards. I think that's quite helpful.
R. Female: Do we have to fight against strange creatures?
Gaia: No you were just asked to be the link between him and that world. In short, you are free to do what in that world, but you can't get into a mess that could destroy that world.
R. Male & R. Female: Fine.
Gaia: I'll do both of your backgrounds and one of you should change the name.
R. Female: Me too! I always thought my name was like a boy's.
R Male: Yes I think if I were in your position I would also think of changing my name.
So what do you want to be named?
R. Female: What about Kazuri?
R. Male: Kazuri huh Mmm..., I think that sounds pretty sweet to me.
R. Female: So from now on my name will be Fujimaru Kazuri please help Oni-can!
{from now on I will use the name Kazuri to call the female version of Ritsuka}
Ritsuka: Aaa….., Kazuri please help too.
Gaia: I will give the servant card to both of you now and unite it with your soul and if you want to use it you just need to say "Install", Ritsuka the servant card that suits you is Charlemagne, and for Kazuri the servant card that suits you is Galahad.
Kazuri : That means I'll be wearing Mash's armor!! (feeling happy).
Ritsuka: You really like him.
Kazuri : Shut up Oni-can let me enjoy it.
Gaia: Good luck to you both.
Gaia starts to make a teleportation circle to move Ritsuka and Kazuri to a very dangerous world but Gaia tells them that in that world there is no magus and magic circuits do exist in that world but there is no term magic circuit so the living beings in other worlds will not know whether You guys have mana, we're just humans from the perspective of those supernatural beings that the two of us were told. And about our family background also carefully made by Gaia so no one will cheat about us, and when we both arrived in this world we both took a look inside our house and when we came out to see what kind of house Gaia gave us we. We both don't know whose house Gaia is copying, but we're glad it's such a nice house.
{The house that Gaia imitated was the house that Shiba siblings lived in}