One of the multiple California-bred champions to arrive during the late 2000s, this daughter of In Excess spent her entire career in her home state.

Owned by Senji Nishimura, Romance Is Diane did just about everything right in her first season of competition. She took three of four starts, all routes, and put her name on the map during the autumn. Initially trained by Doug O'Neill, Romance is Diane moved over to the Mike Mitchell Barn after her debut, winning first time out for her new trainer at Oak Tree. She went on to win the California Cup Juvenile Fillies at Oak Tree and then the Grade I Hollywood Starlet to net Champion Cal-bred Two-Year-Old Female honors.

The first half of Romance is Diane's 2007 campaign was not as strong. Finishing out of the money in her first three starts, all stakes, the dark bay filly regrouped at Del Mar. Part of a three-way photo in the Fleet Treat Stakes early in the meet, she took third in the seven-furlong sprint before finishing as the runner up in the one-mile Torrey Pines next time out.

Always more successful at distances of eight furlongs or more (every one of her victories came at no less than a mile), Romance Is Diane got to try routing again in the California Cup Matron Handicap at Oak Tree. Taking the lead early after racing well behind in both her Del Mar starts, Romance Is Diane never relinquished control in her return to Santa Anita, guiding the field to the wire for another win at the autumn meet.

But something bigger was about to come her way. Back at Hollywood Park for that track's fall session, Romance Is Diane was entered in the Grade II Bayakoa Handicap at a mile and one-sixteenth. Employing the same running style she did at Oak Tree, Romance Is Diane outclassed everyone in the field. Wasting no time getting to the front, she kept the position the rest of the way as she scored her second graded stakes.

Although the first half of her 2007 campaign yielded no wins or placings, Romance Is Diane did enough throughout the summer and fall to win another California Thoroughbred Breeders' Association Award, this one for Champion Cal-bred Three-Year-Old Female.

No victories were to be had in Romance Is Diane's four-year-old campaign, but she was still competitive as she picked up some minor awards. She got the year started with a third in the Grade II El Encino Stakes at Santa Anita, just missing out on second. Next came a fourth in the Grade II Milady Handicap at Hollywood Park, but she returned to claim third in the Grade II A Gleam Handicap at the Home of Champions just under a month later.

Her lone Del Mar trip for 2008 resulted in a fourth in the Grade I Clement L. Hirsch (again narrowly missing third place), but Oak Tree was once again good to the filly. Romance Is Diane shined at Oak Tree throughout her career, and that was true for her last start.

She took on the boys in the California Cup Classic, going a mile and one-eighth. Favored to win the race, she got to the lead in the stretch, and very nearly beat all the boys that day. Only one beat her, that being Mr. Chairman, who got his head in front in the final jumps. But Romance Is Diane put together a hard fought and impressive second place run to finish up her career.

A multiple graded stakes winner, owner of several placings, a solid router, and a two-time Cal-bred champion. Romance Is Diane did a lot in her three years of competition, and the horse with a catchy name stands among the most prolific Cal-breds of her era.