OSAKA, Japan — A Japanese hit single from the mid-1970s has become popular once again, 30 years after its original release.

"Oyoge! Taiyaki-kun" (Swim! Taiyaki-kun) sold more than 4.5 million copies first time round and is still Japan's biggest-selling single. A re-released version of the song on CD has sold about 50,000 copies since March.

Taiyaki is a fish-shaped pancake stuffed with a sweet bean paste.

For the generations that grew up with the smash hit in the latter part of the Showa era (1926-89, named after the Japanese Emperor Showa, more familiar to the West by his personal name, Hirohito), the song offers a feeling of nostalgia, while for young people who have grown up in the subsequent Heisei era (named after the current emperor, Hirohito's son, Akihito), much of the attraction lies in products featuring the song's Taiyaki-kun character.

Observers say the lyrics of the song, which conveyed the frustrations of office workers a generation ago, are now resonating with the contemporary public due to a prevailing sense of stagnation in a society marked by widening disparities.

The song, which was first broadcast on a children's TV program, was sung by Masato Shimon and released in December 1975.

The song starts by expressing how Taiyaki-kun and other taiyaki pancakes are fed up with being relentlessly cooked up on a hot plate day after day. In the song, Taiyaki-kun escapes to the sea, but ends up being caught and eaten by an angler.

The song has become popular once again as part of an increased nostalgia and interest in the Showa era sparked by "Always: Sunset on Third Street," a movie set in Tokyo in the mid-Showa era.

At the end of last year, a toy manufacturer started making stuffed toys modeled on the Taiyaki-kun character as prizes for an arcade game machine in which people manipulate a mechanical claw to pick up prizes. The toy has proved popular among young people, and about 300,000 had been won by the end of March.

Record company Pony Canyon Inc. has released a CD of the song along with a DVD containing an animated film based on the song. The CD peaked at No. 19 on Oricon's chart of the biggest-selling songs and has remained in the top 100 for 10 consecutive weeks. The firm has kept receiving orders for the CD since its release.

"Middle-aged people can enjoy the song and the associated goods together with their children or grandchildren," a company spokesman said.

A 55-year-old company employee said the song had reminded him of the time he started working at the company.

"During tough times, the song helped me to relax," he said. "The character jumped into the sea, but failed in the end. But the lyrics taught me the importance of patience."

"Nowadays, just like at the time of the first release, company employees feel frustrated about working at their companies, and can relate to Taiyaki-kun in the song," economic critic Akira Esaka said. "In this age of insecurity, it's like we're all groping around in the dark. That's why many people are encouraged or reassured by something from the past."

Tatsuo Inamasu, a professor of sociology at Hosei University, said: "In the mid-1970s, when the song became a huge hit, people were more upbeat and had hopes for the future. But people in contemporary society are despairing, and that might be why they are moved by the song."