Pool de Japun!
Tamami forces Haruma into a new job: lifeguard at a pool. He's given some tickets, and brings along Choko and Chitose. Yurika skips her English lesson to visit Choko, but finds nobody home. Instead she gets attacked by a dog and is saved by Kakeru.
Aired 18/10/2006EP 15 - Pool de Japun!
2006
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)