Prosecutors on Friday demanded that a tattooist in Suita, Osaka Prefecture, be slapped with a fine of ¥300,000 for operating without a medical doctor's license.

In a case that has sparked nationwide debate over whether inking tattoos constitutes a medical act, 29-year-old Taiki Masuda is facing a criminal trial in the Osaka District Court for practicing what he considers a form of art.

Prosecutors have charged Masuda with violating the Medical Practitioners Act, saying that tattooists need to be licensed medical doctors as their acts can result in allergic reactions and infections.

Masuda exposed 100 to 150 people to health risks by inking tattoos between July 2014 and March 2015, the prosecutors argued.

The defense team, who say tattooists should be accredited but do not need a doctor's license, will make a closing argument at the next court session slated for Aug. 4.