Acting on a tip-off, police raided the home of Craig Allott, 29, and seized a computer located in his bedroom in June last year.
They found a number of child pornography images, and sudo-images on his computer that were downloaded between June 2013 and June 2016, Michael Tooley, prosecuting, told Sheffield Crown Court.
In total, officers found five 'moving images' that fell into category A - the most serious category, as well as three category B images, two category C images and 155 prohibited images.
The court was told that one of the images depicted a child as young as three being abused.
Allott, of Norfolk Street, Sheffield City Centre was arrested and charged with making and possessing indecent images of children but initially made no comment in police interview.
He later said that some of the sudo-images had been transferred when he downloaded animé and manga images, a form of Japanese animation, on to his computer - and had not intended to download any of the prohibited images that involved depictions of children.
Digital forensic testing carried out by police showed that some of the illegal images had only been partially downloaded, the court was told.
Allott later admitted to the child pornography charges at a plea hearing.
Sentencing Allott, Recorder Richard Woolfall said he believed the 29-year-old had unintentionally downloaded some of the illegal images.
He said: "You had three Category A images involving children, and in one case a child as young as three.
"Children are sexually abused to make these images, and therefore possession of these images is a serious matter.
"It is clear you have an interest in animé and manga material and some of these downloads were accidental - but you were in possession of them and you have pleaded guilty.
"Because of your guilty plea, the fact you weren't searching for them and the fact you have not been in trouble before I take the view that you can be rehabilitated. But if any images of a prohibited nature are downloaded again you will go to prison."
Recorder Woolfall ordered Allott to complete 100 hours of unpaid work and to complete a 20-day rehabilitation activity requirement order.
Allott was also put on the sex offenders' register for five years, and was made the subject of a sexual harm prevention order for the same amount of time.
Under the sexual harm prevention order, Allott is prohibited from owning a computer where internet search history can be deleted and any device he owns that is allowed will be subject to regular checks from the police. He is also prevented from working with children, in a paid or volunteer role.