In 1983, a young engineer at Casio invented the indestructible G-Shock watch. Kikuo Ibe, now the Japanese brand's research and development chief engineer, told Dezeen how he developed the cult product.
Ibe came up with the idea 35 years ago after breaking the mechanical watch his father had given him.
"When I entered high school, my father gave me a watch," Ibe said. "Unfortunately I dropped it on my way to work and it smashed into pieces on the floor.
"So that is the reason why I wanted to create a tough watch that can't be destroyed."
The chunky digital watch was developed at a time when most other watches on the market were as slim as possible, so when Ibe later got a job at Casio, he developed the product in secret.
In 1983, Casio launched the first shock-resistant G-Shock watch designed by Kikuo Ibe called DW-5000C "I used the bathroom to test the shock resistance by throwing watches from the window," said Ibe.
It was not an immediate success, appealing only to construction workers and police officers.
But it later became a style icon when the skateboarding craze hit Japan, leading youngsters to seek a tough timepiece that matched their baggy clothes.
Ibe was in London last month to unveil the 20th anniversary edition of the Mr-G, an upmarket metal version of the original G-Shock.
Read the interview with Kikuo Ibe:

Marcus Fairs: Tell me the story of how the G-Shock came about.
Kikuo Ibe: When I entered high school, my father gave me...