The One Chicago universe has been intact since 2012, and more than a decade later, fans are still clamoring for more stories - despite being inundated with new shows that have similar plots and are in the same genre. Dick Wolf's Chicago Fire started it all in 2012, following firefighters like Taylor Kinney's Kelly Severide as they jumped into action and protected the Windy City from danger. Since its inception, the firefighter TV show has erupted, with series like 9-1-1 and Fire Country all tapping into the same premise. Still, Chicago Fire has remained a favorite for the Us team and viewers throughout America. The fact that the One Chicago universe also includes Chicago P.D., which premiered in 2014, and Chicago Med, making its debut in 2015, has only bolstered the fandom. Sure, Chicago P.D. has to compete with the likes of fellow Wolf series' FBI and Law & Order: Special Victims Unit among other network procedurals - and Chicago Med battles for viewership with hits like Grey's Anatomy and The Pitt - but there's something different about the One Chicago shows. One Chicago's Most Memorable Couples They all have heart, a tie to one of the biggest cities in the U.S. and characters that fans can't get enough of. Scroll down for a deeper look at why Us thinks the One Chicago universe is still standing - even after massive casting shakeups over the past decade: Character Comebacks George Burns Jr/NBC Fans have cried out against beloved characters like Chicago Fire's Matt Casey (Jesse Spencer) and Wallace Boden (Eamonn Walker) leaving the series over the years. They have expressed heartbreak when Chicago P.D.'s Jay Halstead (Jesse Lee Soffer) left the franchise and nearly revolted when Chicago Med's Dr. Will Halstead (Nick Gehlfuss). However, they keep coming back in hopes of character cameos: And boy have the writers delivered. Casey returned to Chicago Fire when Severide (Kinney) and Stella Kidd (Miranda Rae Mayo) tied the knot during season 10. Soffer, meanwhile, has directed a few episodes of Chicago P.D. - and hinted he could return in front of the camera down the line. Earlier this year, both Gehlfuss' Will Halstead and his love interest Natalie Manning (Torrey DeVitto) returned to Chicago Med for an epic two-part story arc that the actors and fans went wild over. Couples Fans Can't Get Enough Of Lori Allen/NBC While all three of the Chicago-based shows are focused on the first responders and their live-saving efforts, the love stories keep viewers enticed even more. Whether it's Casey and Sylvie Brett (Kara Kilmer), who are still talked about but no longer on Chicago Fire, or the Firehouse 51's current power couple, Kidd and Severide, these firefighters can't stop falling for each other, and the Us team is here for it. When it comes to Chicago P.D. there have been plenty of steamy romances, including former partners Erin Lindsay (Sophia Bush) and Halstead, who later dated and married - before divorcing - Hailey Upton (Tracy Spiridakos). The real winner on Chicago P.D., however, has to be the slow burn of Kim Burgess (Marina Squerciati) and Adam Ruzek (Patrick John Flueger). Dubbed "Burzek" by fans, their season 12 wedding was worth the wait. One Chicago's Most Heartbreaking Exits Chicago Med, meanwhile, has given Us Will and Natalie - who are now expecting a baby in Seattle - and the short-lived romance between Dr. Mitch Ripley (Luke Mitchell) and Dr. Hannah Asher (Jessy Schram), which some fans are still shipping. Dramatic Story Lines George Burns Jr/NBC The one thing these three shows are not lacking in is drama. Whether it is the fear of being killed off - which Chicago Fire's Joe Minoso, who plays Joe Cruz, exclusively told Us Weekly in 2022 is something the "cast worries" about "every year" - or the neardeath experiences, fans are always on the edge of their seats. Take Chicago Med's season 11 fall cliffhanger for example: Dr. Caitlin Lenox (Sarah Ramos) was attacked by a known abuser of one of her patients after trying to save the girl's life. As her life hangs in the balance, fans are hoping she not only gets out alive, but is able to help her patient, whom she found dying in the basement of her home. (Not to mention, Hannah being pregnant with Dr. Dean Archer's - played by Steven Weber - baby despite just being friends and having a big age gap.) Introducing New Characters With Complex Backstories Peter Gordon/NBC Even though viewers hate to see OG stars leave their respective franchise, every season brings new talent with even more complex backgrounds. Take Chicago Fire's Sal Vasquez (Brandon Larracuente), for example. He joined Firehouse 51 after being booted from the Chicago Police Department following his father's conviction as a dirty cop. During the 2025 fall finale, Sal's father got out of prison and showed up at the firehouse, seemingly threatening his new normal. Chicago P.D.'s Eva Imani (Arienne Mandi), meanwhile, has come into Intelligence guns blazing, and giving off major young Hank Voi