After his father's murder, Ju Taeseon imagines that his father calls him to eat.
But of course, his father is not there.
After their first investigation, Ju Taeseon takes Lee Chaeha to eat, but he eats far quicker than Chaeha, probably from years of eating alone.
Then, he takes Chaeha out to eat again at the request of Song.
Only to show up at his apartment later and eat his ice cream (from the same spoon) and drink his beer.
After the next investigation, they go eat again, and Taeseon offers Chaeha some of his food.
At the end of the workday, he takes him for another meal without Song.
And now when they eat together, he eats slower.
Beyond Song suggesting they celebrate Chaeha's first day, Taeseon is always the one to suggest eating. Together.
Taeseon is the one who misses eating with someone because even though Chaeha grew up with an abusive uncle, Taeseon is the one who was starved of human connection.