I've been wanting to do a Mokuba-made-the-trenchcoats story for a while (because where else did he get them? Kaiba got a total fashion makeover while in a coma! Very Odd.) and had the line about the buckles in mind all along (really, Yami and he are so competing! Especially in the manga - "I have three buckles on my leather sleeveless shirt thing, *and* two belts!" "Well, I have completely useless straps on my arms and my legs! Beat that! Bwahahaha!!") So the bday was a good excuse. Though how it went angsty in the beginning, I have no idea, I just have too much fun with Kaiba being all tragic-past-y ^_^