Today is the school’s Cultural Festival. 
Yuu-chan is concerned how short her skirt is for the café’s costume.
The four girls, wearing the same costume, are ready to open their café, “Cat’s Tail.”
While the girls are busy with customers, Mai-chan shows up in their café...
That's a retrospective reason...
...إذًا تمّ إضافتها لاحقًا
Also eine nachträgliche Idee …
Qué efecto más inesperado.
Qué efecto más inesperado.
Tu viens d’inventer cette excuse.
È una spiegazione a posteriori.
Então o motivo só veio depois.