Takahiro Shiraishi was executed for the killings in 2017 of nine victims, most of whom had posted suicidal thoughts on social media.

He was dubbed the "Twitter killer" as he contacted victims via the social media platform.Justice Minister Keisuke Suzuki, who authorised Shiraishi's hanging, said he made the decision after careful examination,

Dubbed the "Twitter Killer", Takahiro Shiraishi’s crimes shocked the country known for its low crime rate. Between August and October 2017, he preyed on the vulnerable, targeting mostly young women who had expressed suicidal thoughts online.