Nat is the friendly owner of The Peach Pit, a popular diner in Beverly Hills. He's spent most of his life at the Pit, a huge part of his childhood as it was set up by his late father, Salvatorio Bussichio. Nat is a kind-hearted soul, who cares about people and the neighbourghood. The Pit sets up free Thanksgiving and Christmas meals for homeless residents of Beverly Hills, and Nat is always to give something back to the community.
Nat suffered a heart attack during the fourth season, leading to the possibility of the Peach Pit's closing. Brandon sacrificed much of his time to oversee the diner's functioning while Nat recuperated. The Peach Pit was saved when Dylan McKay bought out Nat's cousin's share. Nat and Dylan's partnership was further explored in season five; particularly during Dylan's massive relapse. During this period, The Peach Pit After Dark made its debut as an after hours night club owned by Nat and Dylan and run by various members of the gang. Dylan stole money from Nat during this point. During Dylan's intervention, Nat pointed out how hurt he was that Dylan stole from him.
During the sixth season, Nat rekindled his romance with his former girlfriend, Joan Diamond, whom he hadn't seen in over two decades. Joan became pregnant, and she and Nat got engaged. She went into labor in the middle of the wedding ceremony and, at the hospital, insisted on completing the marriage vows before going into the delivery room. She gave birth to Nat's only child, a son named Frankie. Nat also escorted Donna Martin down the aisle at her wedding to David Silver in the series finale. Donna's father, Dr. John Martin, died of a stroke midway through the final season of the series.
Nat reappeared in the first few episodes of Season 1, working at the Peach Pit set in a new establishment – this contradicts with his statements on the original series that he would be too old to pick up and start over somewhere else.
- "Ugh! I'm never gonna learn to work this machine. Whatever happened to regular coffee? Willie!"(working an espresso machine)
- – We're Not in Kansas Anymore
- Nat was in the U.S. Navy as a teen.
- Nat inherited the Peach Pit from his father, Sal, who was well known among his clientele.
- According to Nat, his father was very strict
- Salvatorio gave free meals to actor Steve McQueen for two years when Nat was about 10.
- Other celebrities who used to frequent the Pit include Natalie Wood, Cliff Montgomery.
- Both Dylan and Donna remember Nat's dad; Sal used to sneak Donna homemade cookies when she was a kid.