Minnie as her name suggests is a Mini-Digger working in a quarry, alongside full sized heavy duty quarry diggers. She was brought over from Japan with her friend Laurie a small tipper truck and together they provide small quantities of aggregate for minor building companies while the big diggers and trucks produce huge amounts of aggregate for the heavy construction industry. The big machines laugh and joke about Minnie and Laurie and are generally unkind to them due to their diminutive size. However, when Digby, the newest and brashest digger gets buried while working in the quarry only Minnie and Laurie can save him. Thereafter the big diggers and trucks have a new respect for Minnie and Laurie and they all work happily together in friendship and harmony!