Ashton, Topher Departing 'That '70s Show'

The Formans' basement is about to get a little less crowded.

After seven seasons, up-and-coming stars Ashton Kutcher (search) and Topher Grace (search) are putting "That '70s Show" (search) behind them, opting to leap into the present and pursue other projects.

But by the hugs and tears at the finale, you can tell the decision was bittersweet.

"We started when we were so young and we really grew up through this experience together and ... it's gonna be really hard for me," Grace told FOX News.

In Wednesday night's season finale (8 p.m. EDT on FOX), Eric (Grace) is leaving to teach in Africa, but he can't get to the airport when the car won't start. As for Kelso (Kutcher), he's driving Jackie (Mila Kunis) to Chicago ... but why he's departing Point Place won't be revealed until the fall.

Both now-hot actors got their start on the show. Kutcher, who now dates Demi Moore (search), says he can't even watch himself in the first season.

"I really thought I was gonna get fired off of the pilot. I think I've improved as an actor thanks to this show," Kutcher.

But before they ride off in the Vista Cruiser, a soon-to-be former cast mate has parting words.

"We're such a big part of each other's lives, you know what I mean? It's almost that we're never gonna leave each other's lives," Wilmer Valderrama (search), who plays Fez, told FOX.

It's hard to say goodbye, but Valderrama knows it's the best thing for his co-stars.

"I cried. It was really hard, actually. One of those times you really see this incredible team. But the two of them are making choices, and I am super proud of them and knowing they're doing amazing stuff."

As for Fez, Hyde, Jackie and the rest of the gang, they're sticking around for at least another season.

"Most of the cast are going to be there and the fans -- you know, the fans have been watching for seven years straight, and they are still. So, I figure why not we do one last year of crazy, you know controversial, scandalous episodes? We're definitely going to get in trouble next season. Every single one of my friends will be a guest on the show. That'll be fun."

And are we finally going to learn what Fez's nationality is?

"We will find out where Fez is from this year," Valderrama told FOX.

FOX News' Lisa Bernhard contributed to this report.