Bacteria, which are small, invisible organisms, have continuously combated viruses. While bacteria have implemented diverse defense mechanisms to prevent infection, they often incorporate and customize non-infectious viral particles for their own purposes. It was precisely when I started research and realized their intricate relationships that SARS-CoV-2 became prevalent worldwide, severely impacting our lives. The anxious atmosphere among people at that time strengthened my interest in the ways bacteria integrate viruses into various cellular systems. I believe that these small neighbors hold clues to this somewhat philosophical question: Where does the relationship between life and viruses ultimately lead us?