The Banshin had been built in a day rather than 500 years, and Nyarko, Kuuko, and Hasuta are ordered to leave Earth as a result because they aren't needed anymore. The group goes to check to see what the Banshin actually is, as it determines if they really do have to leave or not. Will Mahiro have to say goodbye to Nyarko, Kuuko, and Hasuta?
But we don't mind them 
staying at our place longer...
Pero no nos importaba que se 
quedasen cuanto hiciera falta.
Aunque no nos importaba que os quedaseis el tiempo que hiciera falta.
Eu não ligo se eles quiserem 
passar mais um tempo em casa.