Ramon Cardenas studied filmmaking during high school, but even he couldn't have written a script where he fought for The Ring/Undisputed junior featherweight championship.

But that's exactly what will happen when Cardenas, rated at No. 9 by The Ring in his class, faces pound-for-pound star Naoya Inoue on Saturday at T-Mobile Arena in Las Vegas.

Inoue-Cardenas, plus undercard action, will be broadcast on ESPN, ESPN Deportes, and ESPN+ at 10 p.m. ET.

"I'm just grateful. I always said I wanted to fight for a world championship, to become world champion and to fight for undisputed is more than I could ask for," Cardenas (26-1, 14 knockouts) told to The Ring. "I'm just going to go out there and take advantage of this opportunity I've been given.

"I see the same thing you guys see. I'm never going to discredit him. He is a four-weight world champion. I know going into this fight I have to be perfect for 36 minutes because I know he's going to come with everything he has."

Cardenas believed that unbeaten Mexican Alan Picasso initially had the assignment to face Inoue on Sunday, but when the chance of a lifetime came his way he grabbed it with both hands.

"That was funny because I just fought the week before, I was picking up food because I had no plans on fighting," he explained. "My manager, [Michael Miller] calls me and we're talking about something else and out of the blue, he was like, 'Would you like to fight Inoue?' I was like, 'Yeah, I've been telling you that's a fight I would like. He's one of the best in the world, so I think to say you're the best you have to fight the best.' And then, he's like, 'Would you like to fight him May 4?' I'm like, 'Seriously?' He's like, 'Yeah.' I'm like, 'Damn, of course.' That's basically how it happened. From one conversation everything happened super-fast.

"I told my manager, agree to everything, as funny as it sounds, 'If my trunks have to be pink or my underwear yellow it doesn't matter.' To fight one of the best fighters in the world, it's a dream."

The San Antonio native has worked jobs for Lyft, DoorDash and Uber to make ends meet while he worked his way up the ranks.

"The money is good, but it's the opportunity to fight one of the best fighters in the world,” he said. “Money is great, but if I really wanted money I'd go get a job. I might not make the same money, but I'd work 9-5 and don't take hits for a living. I've always dreamt of being a world champion and I'm having my opportunity to fight one of the best fighters in the world, and what better way to become world champion after beating this guy?"

Not many, if any, outside Cardenas are giving him a shot at victory. In fact, he's as much as a 25/1 (+2500) underdog with some bookmakers.

The proud Texan, who is training in Indio, California, with the well-respected Joel Diaz, isn't paying any attention and is confident he can pull the upset.

"Knowing what I can do, what I'm capable of doing, that's what really gives me confidence," he said. "I'm lucky to have a good team behind me. I don't need anybody else to believe in me accept the people that are close to me.

"Nobody believed in Buster Douglas. No one ever in a million years thought Buster Douglas was going to beat Mike Tyson and look what he did. It's unbelievable until it's believable. And it's unaccomplishable until it's accomplished."

Meanwhile, the budding director, who in his sophomore year in high school won an award in his city for a film in which he played the lead role in as a young boxer being bullied by his older brother, foresees a storybook ending followed by a mic-drop moment.

"[Inoue] comes to Vegas, and it would be an upset," Cardenas said. "[Inoue] goes back home and then we fight in Japan, I beat him again and I retire. I've got nothing else to prove in boxing."

Inoue devoured all before him en route to world titles at 108, 115, 118 and 122 pounds. The big-punching Japanese “Monster” has lived up to his moniker, demolishing the likes of Omar Narvaez (KO 2), Jamie McDonnell (TKO 1), Juan Carlos Payano (KO 1) and Emmanuel Rodriguez (KO 2).

However, it’s his triumphs over four-weight world champion Nonito Donaire that provided Inoue with considerable acclaim. He edged Donaire (UD 12) in an instant classic that was later named 2019 Fight of the Year by The Ring and stopped him in the second round of their rematch.

The 32-year-old became the undisputed bantamweight champion when he dominated Paul Butler, stopping the Brit in 11 one-sided rounds. With nothing left to conquer at 118, Inoue moved up in weight and looked just as impressive as ever bludgeoning Stephen Fulton (TKO 8), the consensus No. 1-rated junior featherweight, to add the WBC and WBO 122-pound titles to his growing list of accolades.

He claimed the vacant Ring championship and IBF/WBA titles against Marlon Tapales (KO 10) to become undisputed junior featherweight champion. Inoue got off the floor for the first time in his career to dominate former two-weight world champion Luis Nery (TKO 6) in front of a huge crowd of more than 40,000 and has since beaten TJ Doheny (TKO 7) and Ye Joon Kim (KO 4).