All is set for the fifth season of Fox's "New Girl" and some things are about to change as the tenants make a long overdue decision to grow up.

Fans are exceptionally eager for the next season after Season 4 closed with an explosion -- Schmidt's (Max Greenfield) reasonable but impulsive proposal to Cece (Hannah Simone).

The milestone will bring in new challenges to the relationship of the couple, and create changes to the lives of the people in the house.

"There's been a lot of really funny stuff we've done over the years with them being incredibly immature, but it felt like the right moment to let them take steps forward," creator Liz Meriwether tells TVGuide.com. "We've been having an amazing time this season growing the characters, and it's resulted in more comedy, not less comedy."

In the past, the characters evolved into their better selves, bringing in a new color to the show.  Nick (Jake Johnson) steps up to run the bar and Winston (Lamorne Morris) settles into being a cop.

As the show enters its 5th season and airs its 100th episode, it feels the need to reinvent itself like many long-running shows.

Meanwhile, the story is affected by the production's off-screen challenges. Damon Wayans Jr., who plays the athlete Coach, is set to depart after season 4. "New Girl" herself, Zooey Deschanel, will only be around for five episodes due to her maternity leave.

Like their onscreen counterparts who are all glad for Jess doing jury duties, everyone on the set is exhilarated by the occasion.

"I'm glad Zooey took the time she needed, and it was a great challenge in the fifth season to have to do 'New Girl' without the New Girl," Meriwether says. "I'm really proud of the episodes."

Following the fifth episode, there will be two episodes which mainly revolve on Nick, Schmidt, Winston, and Cece, who will deepen their relationship with one another. Meriwether is thrilled with Cece and Winston's growing friendship. The two never interacted much before.

The remaining four episodes of the show will bring in guest star Megan Fox as pharmaceutical rep Reagan who sublets Jess' room.

The new lady is Cece's old friend who she met at the 2003 MTV Beach House.

Reagan, who is tough and rational, will see her co-tenants in a different perspective. This girl is not into weirdness.

"It's been funny to have an outside perspective looking at our group and being like 'you guys are a bunch of weirdos,'" Meriweather adds.

Jess comes back after Fox's arc and the episodes following her return will see Jess and Nick settle unresolved feelings for each other. Meriwether held fans from being excited by killing any speculations of romance between the two characters.

If there's someone who's bound to fall in love, it will be Winston who is set to be smitten by Aly (Nasim Pedrad).

Moreover, the season will also feature the road to Schmidt and Cece's marriage.

"New Girl" season 5 premieres Tuesday, Jan. 6 at 8/7c on Fox.