"Farewell, then" he says, and he leaps out your window, going back to wherever he came from. The wand feels a bit warm in your hand, but nothing unusual.
3 years later, late December.
Small flakes of snow falls gently from the sky so delicately, there is an aroma of sweet cakes being baked in the streets, and people are packing the metro stations. Just from seeing, hearing, and smelling this, you know it's almost time for the new year, and you sigh to yourself. Yet another year has gone by, but you can't dwell on it for too long, since you need to go home quickly and order dinner before the restaurants close.
Arriving at home, you sit on your bed and sip on the hot Darjeeling (with 5 spoons of sugar and some milk, of course), and stare at the scenery outside. The snow fall, fall, falls like cherry blossoms in early April, and as you prepare to bring the cup to your mouth you see something on your bookshelf.
An azur wand? You grab it, and remember that day's decision, two winters ago. That's when you had chosen to be a normal human, and somehow you ended up here, no better off than before.
"Well, every time you become 18, your life will be reset, and you go back to the day you were born! You will have no memories of that time, and be able to live endless childhoods. How does it sound?"
Did you make the wrong decision then? It's a shame you'll never get another chance. You're thinking you might have made a bad decision when you hear:
How does it sound?"
You realise it's not from your memories, but from a little cat sitting next to you. She looks pleased with herself, and a bit arrogant of an expression on her face. She reminds you of Nozomi, but somehow you know her name is actually Koko.
"Why don't you sign a contract with me?" the cat asks.
"A contract?" you wonder. Your mother had told you not to sign contracts without asking what they're for.
"Well, if you sign the contract, you'll become a magical girl: incredibly happy and never lack anything in your life again! The only cost is that we need to use a part of your brain to make you magical so you'll forget all the memories you've made up to this point, but you'll be perfectly capable of making new memories. You'll also have a youthful body forever."
"I don't know if that's that I want..." you tell Koko.
"Alright, then how about this? If the last one was contract (A), this is contract (B). I know you enjoyed your childhood a lot, so contract (B) only means you can't make new memories from 10 years after the day you begin, but you can keep all your previous memories. Of course the youthful body part remains the same."
You think for a moment, wondering whether or not to sign the contract (A) or (B) in front of you. Will you do it?
Remember, you are 30 years old.
Contact (A) will erase the first 30 years of memories, and you can make memories after that.
Contact (B) will erase any memories after the first 40 years, but you can still act normally.