The first card shows up on her tenth birthday. Raimei comes out onto her doorstep and finds it there, a little pink envelope with a holographic rainbow sticker holding the flap closed. She decides it must have been delivered personally, and looks around for whoever might have dropped it off – maybe one of her friends from school in the surface world? - but there's no one around.
Raimei opens the envelope carefully, noting how delicate the paper seems to be – stationery, probably handmade, pink (her favorite color when she was younger) because at some point it had been cherry blossoms – and slides the card out. It seems to be made from the same paper, but a lighter color and smoother texture. Across the front is painted the character for "strength", and the inside is blank except for a small pocket.
Nestled there is a typed note that reads 'Take care, and try to remember to pack your lunch – Happy Tenth' and a five thousand yen bill. Raimei scours card, envelope and note alike for a return address or name, but there is none.
She spends the five thousand yen on a new set of dumbbells.
-+-
The next card – heralding her eleventh birthday – arrives in her mailbox, not on the porch, but still there is neither stamp nor return address. The paper this year is orange, again made from a special press, and Raimei thinks she can see the remnants of pansy petals in its grain. The card this time wishes her the virtue of "perseverance", and Raimei wonders how this mysterious card-sender could know she's been slacking off in her workouts lately.
Inside is another note, reading, 'Don't forget your s-m-i-l-e,' with an ugly little doodle serving as an example, and a bill like the previous year's. This time, Raimei puts half the money in savings and spends the other half on polish for Kurogamon.
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On her twelfth birthday, the card is a pale mint green and accompanied by a box of little homemade carrot cakes.
The words are simply, 'Thinking of you always,' and the bill is ten thousand yen. Raimei is surprised to find that guessing the identity of her mystery birthday-benefactor has become almost like a game to her, and she realizes with annoyance that her opponent is still holding all the cards.
She spends the money on getting Kurogamon professionally cleaned and tuned up, at a really classy place. These last few months, she's been closing in on Riakou, after all.
-+-
She's lost her brother's trail again, but the cards are just as impeccably timed as ever. This one shows up in her locker at school and she has to wonder, how did it get there?
She opens it in the bathroom, glad she's safely hidden in a stall where no one will see the way she blushes. Somehow, receiving all these cards feels...contraband, or something. And she's always felt guilty that she doesn't know who to thank for them. But she pushes the thought out of her mind when she sees that it's yet another ten thousand yen bill. With this, she could repair the crack in Kurogamon's sheath; she could buy a gym membership for a year; combined with her savings, she could almost hire someone to track down Raikou for her –
Then she sees the writing on the card.
Beneath its gift, the newest card has a regular old birthday wish on it, and some cheeky advice that makes Raimei huff and wonder, again, how the hell the sender knows what she's been spending the gift money on.: 'Use this to buy yourself some CUTE JEANS OR A SHIRT, or something.'
Reluctantly, she does.
-+-
'MeiMei - '
Raimei's eyes sting and blur, and she crumples the card and throws it in the trash. The opponent has forfeited; she's won the game.
Her stomach is tied in knots for the rest of the week.
-+-
Raimei spends her fifteenth birthday in a hospital.
The last card (still unsigned, though she's certain the sender must be aware that she knows who he is) appears on Raimei's bedside table while she sleeps in the scratchy hospital bed she hates so much, and the word scrawled across the front could be either "sympathy" or "apology". The inside is blank, but someone seems to have written in pencil and then erased several different messages. She can barely make out the words "trust" and "remember". Just below them, erased almost completely, might be "I love", but she tells herself it isn't there.
Tomorrow will be the day she goes out to claim justice; she can't do that with a heart full of doubt.
For some reason, though, she still keeps the card in her pocket when she goes to meet the ghost who's been haunting her for five long years.
-+-
Shimizu Raikou sends his sister a birthday card every year until she turns fifteen.
On her sixteenth birthday, he puts his hand on her shoulder as she blows the candles out and whispers the message he erased and re-wrote and erased so many times from last year's card into her ear.