It's Zakuro-chan! Dokuro-chan! / It's Goodbye! Dokuro-chan!.Episode 7 - It's Zakuro-chan! Dokuro-chan!: Sakura meets Zakuro where she explains that she needs to take Dokuro back to the future.
Episode 8 - It's Goodbye! Dokuro-chan!: Sakura is left with a choice if he wants Dokuro to stay with him or not.