A 57-year-old man admitted during the first court hearing of his case Thursday to trespassing and other charges over an incident last April in which knives were found on Prince Hisahito’s classroom desk at a Tokyo junior high school.

Kaoru Hasegawa, a resident of Kyoto, said there was “no mistake” in the allegations presented against him at the Tokyo District Court.

The imperial succession May 1 last year promoted Prince Hisahito to second in line to the chrysanthemum throne after his father Crown Prince Fumihito, 54, the younger brother of the 59-year-old emperor.

The trial concluded later in the day with prosecutors seeking an 18-month prison term, and the defense team requesting a suspended sentence. The court will deliver its ruling Feb. 14.

Prosecutors submitted two knives with their blades stained pink as evidence, saying the defendant “had always held a personal interest in the imperial system.”

“His motive was to draw public attention,” they said.

Hasegawa apologized, saying his actions were “reckless” and “unforgivable” but did not touch on the imperial family.