Janine Melnitz is the love interest of Louis Tully in Ghostbuster 2 and Egon Spengler.
Janine is highly sardonic with her eccentric bosses while taking her job in such an unusual business in stride. As such, no matter how strange circumstances become at work, she is largely unflappable. Her hobbies included racquetball and reading.
In the first film, Janine showed romantic interest in Egon, but by the second film, begins a relationship with Louis Tully.
In Ghostbusters II, Janine's appearance is very different from the first film; she now has red hair, a new hairstyle, and wears humongous glasses. This new look was perhaps influenced by the Real Ghostbuster cartoon series, which was popular at the time.
Janine was the first person hired to work at the Firehouse. She staffed the phones and kept track of appointments, calls, messages, etc. While initially extremely bored with her job, once the boys picked up more and more clients, she began to complain of being overworked.
After Dr. Venkman implied that perhaps she'd find more pleasure in another low-wage job, she took offense, but stopped her complaints.
When Walter Peck showed up to shut down the storage facility, she tried to stop them, but the Police Captain, along with all of Walter's paperwork, gave her no choice.
Before the explosion at the firehouse, she kept watch with Egon Spengler over Louis Tully.
After the guys blow up the Stay Puft Marshmallow Man, sending Gozer back to its own dimension, Janine is seen at the entrance of the building, hugging Egon, as he heads to the Ecto-1.
In late 1989, Janine was re-hired following the Ghostbusters' capture of the Scoleri Brothers during their trial. She soon responded to a new phone call. After hearing what the customer says, she smiled and replied, "Yes, we're back."
In the weeks after, the Ghostbusters were flush with business. In one instance, she was entrusted with two Traps by the guys and walked off to deposit the ghosts in the Containment Unit. She becomes attracted to Louis Tully, the staff accountant.
Venkman hired her to babysit Dana Barrett's son Oscar while he went on a date with Dana. When Louis asked her out, Janine had to decline but invited him to instead come with her to babysit.
They ended up making out in Peter's apartment. Later, when the Ghostbusters are stuck at the Manhattan Museum of Art, she lends Louis one of Egon's uniforms.