Ultraseven: S1 E47 - Who Are You?

After returning home drunk, salary man Sato encountered his family and neighbors from his apartment and is told "we don't know you"; he is devastated and eventually disappears. TDF heads out on an investigation after receiving a call from Sato earlier. Dan and Furuhashi find out that Alien Huk has been swapping residents during the night, to turn the apartment housing complex into an alien residential area.