Giving Her a Sign of His Devotion : Courtship: Thwarted by repeated refusals, a suitor attempts a public plea for his girlfriend’s hand in marriage.

Some people just won’t take no for an answer.

Consider 44-year-old Malibu artist Hiro Yamagata. For six years he’s been pursuing Shannon Cleye, who at 32 has been flattered by all the attention but who says she “just wanted to be friends.”

Undaunted, Yamagata has proposed to her repeatedly over the past year. He telephoned from remote parts of the globe and left messages on her answering machine. He flew Cleye and her mother to Bora Bora, presented her with a hefty diamond ring and proposed again.

But to these and other matrimonial bids, the answer was always the same--no.

In desperation, he turned to a billboard on the San Diego freeway just east of Los Angeles International Airport to get his message across. Erected a few days before Christmas, the billboard read: “Shannon . . . I can’t live without you. Marry me in the sky.”

Since Cleye frequently drives from her Seal Beach home to Malibu, where she is helping to oversee the construction of Yamagata’s new home, he felt certain she would see the sign.

But just to be sure, he invented a story about a billboard he rented to publicize an upcoming art show and asked her to look for it.

“I had actually seen the (Shannon) sign,” Cleye recalled, “but was completely oblivious that it might be me. I just remember thinking, ‘How about that, a girl with the same name as me. She must be the luckiest girl in the whole world, a guy that loves her that much.’ ”

But because the billboard was unsigned, she didn’t make the connection until later.

“I saw it again when I was stopped in traffic. All of a sudden it occurred to me, and I just started crying in my car,” said Cleye. “The guy in the next car looked at me, and I pointed to the sign and I pointed at me, but he probably thought I was just another insane person in California. I could barely drive after that.”

Yamagata’s message was a reference to their frequent globe trotting--he with art exhibits and she in her job as a publicist for several multinational corporations--and the difficulty they encounter making their schedules coincide.

“The original idea was, marry me in a plane, during a flight, because we are always traveling,” said Yamagata, a successful artist whose paintings and prints sell for upward of $200,000 each, according to art experts. “It’s very hard to reach each other, so the only way we would ever get together is in the sky.”

But even after seeing the billboard, Cleye was elusive. Her answer? She promises she’ll make it known soon--where else?--on a freeway billboard.