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 thought that it'd taken a long, long time,
Ich glaubte, dass es zwar lange gedauert hat,
Pensé que había tomado mucho, mucho tiempo,
Había tardado muchísimo,
Que même si l’attente avait été longue,
il était venu tenir sa promesse.
Achei que, depois de tanto, tanto tempo,