Harem End

Itou Seita was supposed to be an ordinary college student, but suddenly he found himself in an anime-like situation when 5 girls -- alien, little sister, childhood friend, tsundere, and fiance -- showed up in his apartment and decided to start living with him. Is this your typical harem or is there something else going on behind the scenes?
A formerly popular but now disgraced and unemployed seiyuu/idol Hira**** Aya gets a generous proposal to voice the lead part, magical girl Killemall, in a mysterious animation company production. But is that company harboring certain secrets?
Finally, how do these two stories connect together to lead to a perfect harem ending?

Also, contains 5 extra short stories.