One day, Jong-woo, the grandfather who came to the house where Jae-sang and Ah-yeon live, came to say their last goodbye.
At the same time, Ah-yeon is strangely wary of and suspicious of Jong-woo. Meanwhile, Jong-woo makes a shocking confession to Jae-sang.
"I'm an alien."
Between Jong-woo's curious words and Ah-yeon's doubts, Jae-sang grows by forming his own values.
