Was there a specific reason Yuki was confined for a short amount of time?

*spoiler*
I think when Kureno got released from the curse Akito freaked out and started to abuse the power she had over them all

Well I know when he was little he got sick fairly easily.

It is because he disobeyed Akito and he needed to be taught a leason দ্বারা getting whipped দ্বারা Akito.