Nimi-san has gone against the Shinsengumi. To avoid anymore problems they want to get rid of Serizawa.

I couldn’t possibly take them with me.
لا أستطيع أخذهما معي
kann ich sie unmöglich mitnehmen.
non posso portarmeli con me.
não posso levá-los comigo.
забрать их с собой невозможно.