HAPPY☆LESSON ADVANCE: Bau Bau★Kanna no X'mas Soudou

One day, as Christmas approaches, Chitose spots a puppy in town. It turns out to be Chibisuke, the puppy she had rescued and cared for after an accident. Concerned about Chibisuke, Chitose goes to check on him, only to encounter Kanna, who had been searching for Chitose, determined to claim her for herself...

(Source: Bandai Channel, translated)

Note: An unaired episode included with the fifth DVD of the Director's Cut edition of HAPPY☆LESSON ADVANCE, taking place between episodes 9 and 10.