I LOVE THIS PAIRING!!! it's so bittersweet!! I thought this statement really fit them.
Gin saved Rangiku from starvation and they became friends after that. Rangiku's birthday is the day she met Gin because she only started counting the days once she met him! Awww! But after Gin betrayed Soul Society, Rangiku was devastated. I think what haunts her the most is that Gin said "sorry" to her before he left, which shocked her greatly.
I hope you all enjoy! Please hug/fav/comment!! Comments are appreciated greatly!