The Mr Men captured the imagination of generations of children. Now the cartoon favourites are being brought into the 21st Century by the son of their creator.

This year, we will be introduced to the crazy worlds of Mr Cool, Mr Rude, Mr Good, Little Miss Scary, Little Miss Bad and Little Miss Whoops.

The new books have been drawn and written by Adam Hargreaves from Mid Sussex. He has taken over the mantle from his father Roger Hargreaves, who died in 1988.

Adam and his sister Amelia Beddoe have run the Mr Men company for the last 15 years from a farm-based office near Tunbridge Wells.

Until recently they feared creating new characters would be too much of an intrusion into their father's territory.

All that changed when they ran a competition for children to design their own limited-edition Mr Man or Little Miss, to raise money for the charity Children With Leukaemia.

Adam, 39, said: "Until last year, I simply felt it was not my place to add to what my father had done. It was the combination of running the competition and my growing confidence in what I was doing that changed my mind.

"After working on them for 15 years, the Mr Men are just as much a part of me as they were my dad. It no longer feels like an intrusion on his stomping ground."

Adam's characters have been coloured in on the computer, unlike his father's, which were coloured by hand with Magic Marker pens.

Despite his different methods, Adam has promised the new books will retain the unique style that has made his father's series such a success for the last 32 years.

He said: "I have tried hard to capture my father's style. Once you have an idea for a story, the books are to a degree formulaic, with recurrent themes. It's just getting the idea that can be difficult.

"The characters may look slightly different to my father's but they have retained the same bold shapes and colours."

Books featuring Mr Cool, Mr Rude, Little Miss Scary and Little Miss Bad will go on sale in April. In September, the Little Miss Whoops and Mr Good books will hit the shelves.

The new books take the number of Mr Men created by the Hargreaves family to 46 and the number of Little Misses to 36.

They will be in the same format as previous releases - small, white soft backs. Even Roger Hargreaves' name will be retained on the front cover.

Adam said: "Because the name Roger Hargreaves is synonymous with Mr Men, we decided to keep it on the front cover. At the end of the day, the Mr Men were his creation."