Blue Flame Assault

Both include firefighting as a central theme. BLue Flame Assault focuses only on firefighting but the first responders focuses on a range of different first responders.

My Fireworks on Earth is also a firefighter drama with a firefighter male lead.
There's romance in both shows

Both dramas are about fire fighters
but I hope Blue flame is better than flaming heart
because the romance destroyed that other one

The main plot in both dramas is that the ML's are firefighters. There's a comrade around the firefighters (much like in a date with the future) and there's romance in both.

In both shows the leads are socially awkward outcasts. They also idolize their popular love interest.