Chapter 19:
Koto takes her mother from the Shrine's Holy Grounds to the Looking Glass City.
Chapter 20:
The three siblings enjoy their time with their mother, but...
Chapter 21:
Koto tries to find out the secret of her birth from her mother, but instead she's asked to save her poor father.  With no place for her feelings to go, she takes them out on Myoue.
I've been looking for you this whole time!
Ich habe die ganze Zeit nach dir gesucht.
¡Te estuve buscando todo este tiempo!
¡Te he estado buscando 
todo este tiempo!
Je suis à ta recherche 
depuis si longtemps !
Estive te procurando esse tempo todo!