A Heroic Spirit's Diary of Raising Kids

The legendary Throne of Heroes connected to Chaldea.

Wasn't there supposed to be only one Master?! How did a three-year-old kid show up, and why did all the Heroic Spirits seem to know her? Chaldea now had to save humanity and take on the important task of raising a kid (crossed out).

As one of the extra Masters, Rin needs to repair Singularities, but why are they all so weird?

Scene One

To repair a Singularity, little Rin starts summoning.

First: Ryomen Sukuna

Little Rin: “Acha!”

Ryomen Sukuna, fighting Yuji for control of his body: “Brat, do you want to die?”

Second: Oda Sakunosuke

Little Rin: “Acha!”

Oda Sakunosuke, who thought he'd died after going down with the boss: “???”

Third: Atobe Keigo

Little Rin: “Acha!”

Atobe Keigo, getting ready for a tennis tournament: “???”

The real Archer (picking up little Rin): “Don't go calling just anyone Archer.”

Scene Two

Little Rin starts summoning again.

First: Aizen

Little Rin: “Daddy!”

Aizen: “When did I have a kid?”

Tokiomi (unable to maintain his elegance): “Rin, I'm right here!”

Second: Shinnosuke Nohara (adult version)

Rin: “Huh?”

Cu Chulainn (sulking): “Why isn't the young lady calling my name this time?”

Third: ...

A Chaldea Scene

Mash [in disbelief]: “Senpai, when did you get an illegitimate daughter?!”

Fujimaru Ritsuka [covering their face]: “I don't have one... Let me explain.”

EMIYA [getting all kinds of outfits ready]: “Rin...” (Cute, cute, cute.)

Cu Chulainn [slinging her over his shoulder]: “Young lady, let's go for a drive!”

Ishtar, Ereshkigal [starry-eyed]: “Wow, so this is what I was like as a kid!”

Artoria [her ahoge wiggling]: “As expected of Rin!”

Gilgamesh [unusually patient with kids]: “You like jewels? Here!”

Medea: “Please don't teach her Bajiquan!”, From Caster, who was badly injured in close combat by Rin in the UBW route.

P.S.:

1. The joke is that Guda is Rin genderbent. I thought of the three Rin faces in the Babylonia anime and cracked up.

2. Daily-life story, with plenty of voice actor jokes.

3. Little Rin in Fate/Zero was just too cute, which gave me this idea.

4. There will be other worlds, too!

5. A child-raising story. Archer is Mom!

Theme: Raise little Rin