From the manga "Lament of the Lamb", focused mainly on the two first volumes of it, so I don't think there is any spoilers in it.
Chizuna, one of a many main characters, is the main focus in this video, looking back at her past and comparing it to her present, especially at the new encounter of her brother who left home young due to the family's "abnormal" problems.
Chizuna is a cold young girl, and even though those she is surrounding by are supportive and loyal to her, the only two people she only let in to her heart was her father, who is now dead, and her brother, Kazuna (If you can't pick out the difference between the two, Kazuna is the one that looks more frightened, and a little bit younger).
Hope you all enjoy, and thanks for watching! :)