Setagawa was your childhood friend, but you separated when you were in high school, Setagawa left you because he had to go with his parents.

Then Setagawa went to Japan, because he was applying for a job, and he didn't know that you lived in Japan

And you are also applying for a job, when you want to be interviewed, there is also a colleague next to you who is being interviewed.

After the interview, you both left the interview room, you grabbed Setagawa's hand, then Setagawa said

"Who?"