Shinji Miyadai, a sociologist who was assaulted on a university campus in Tokyo last week, has been discharged from hospital and said he is ready to resume work in a video message released Wednesday.

"I suffered serious physical damage," Miyadai said, appearing in the video with bandages over the left part of his head following six hours of surgery. "But my mind has not been damaged," he added.

The 63-year-old professor at Tokyo Metropolitan University said he may resume working as an academic and pundit online for the time being, and hopes he will return to such activities in-person after finishing rehabilitation.

Miyadai, known for his writing on girls dating for money and the now-defunct Aum Shinrikyo doomsday cult, was taken to hospital after being seriously wounded in a suspected knife attack at the institution's Minami-Osawa campus in Hachioji on Nov. 29.

The suspect is still at large and the motive remains unknown.