Downpour, and -
During a rainstorm Haruma gets a call from Ayano saying that she will be moving to the countryside with her finance. Noticing Haruma's depression Choco asks Chitose and Makoto for help, she eventually writes a letter to Ayano explaining Haruma's feelings about her, Haruma gets angry which makes choco run away. Haruma reads Choco's diary afterwards.
Aired 27/09/2006EP 12 - Downpour, and -
Chocotto Sister
Haruma Kawagoe is an only child. A long time ago, at Christmas time, his mother miscarried the child that was to have been his baby sister. That night, young Haruma knelt down and offered up an earnest prayer: "Please make my mother well again, and please give me a little sister." Years have passed, and Haruma has nearly forgotten his prayer. But Santa hasn't.... one Christmas, when Haruma is least expecting it, he gets an unusual present - his sister.
(Source: Anime News Network)