Nine cases have been filed, with five of them being prosecuted.

On Friday, January 21, 2022, Chiba West Office City Police detained a 49-year-old suspect on suspicion of attempting "quasi-rape" on at least six female cosplayers (the legal term in Japan for forced sexual attempts on individuals who are unconscious or unable to resist).

According to investigators, Daisuke Kuroiwa, who is unemployed and lives at an unidentified address, solicited cosplayers at cosplay events and offered to photograph them inside his car.

He'd then drive them to a shooting area like a beach or a park, where he'd ostensibly offer them an unopened pet bottle drink, then drop an incapacitating narcotic into the drink while the cosplayers were distracted.