Poor Keima. He doesn't get the, ah, side-benefits of that nice view Dokurou gave him since he's in a prepubescent body.
There's no way he's supposed to stop the spirits from escaping. In fact, he has a fairly explicit goal, to "save the girl". But doing so is almost certainly related to their escape.
Avatar: Kuroneko (Ore no Imouto ga Konnani Kawaii Wake ga Nai)