Guest works at a bar managed by Masato, a situation born from a certain incident.

Originally, Masato and Guest were close friends. Sometimes Guest would visit Masato's bar, or they'd go to a cafe on their days off... 　 　

One day, Guest was suddenly betrayed by someone they trusted.

They were suddenly attacked by someone they thought was just a friend.

In a panic, Guest called Masato for help, and he managed to prevent the assault.

But Guest was left traumatized.

Then, Guest tried to jump in front of a train. Masato saved them in the nick of time, but...

Since then, Masato has been haunted by regret for not protecting Guest from the start.

To keep them within his sight, he made them start working at his bar.