Here's a short reply! Sorry, I wrote this at 2AM when inspiration hit...

Dear Mr. Akashi Seijuurou:

Hi! As you already know, my name is Furihata Kouki-you already know, because you recently sent me a pretty long letter detailing how you fell in love with me. And even though I'm sure you don't need a reply now, I just want to say "thank you". Thank you, for falling in love with me, for writing that letter and putting your soul into it, and for giving me so much confidence with your love, that I have to pinch myself everyday to make sure that this isn't a dream.

You know...I really wish that I had even half of your eloquence in that letter, because when your name pops up, it fills me to the brim with happiness-because you're such a brilliant person, and not without your flaws but so, so perfect at the same time-yet I can't even write a paragraph to detail my feelings. You make me so happy, and all I can say is yes, I would go out with you. I love you so much, so much that it hurts, and I want to spend my life with you.

I love you, Sei.

...But hey, babe, next time you confess to someone via a letter, give that letter to the person before the third year of your wedding anniversary, kay? I really would have preferred this over randomly showing up in front of my school with a ten-foot limo...but eh, there won't be a next time. Still, this is cute, and the fact that you didn't have the guts to give this to me earlier is even cuter.

Love,
Furihata Kouki.