On Jan. 18, manga artist Hinako Ashihara tweeted from her new X social media account the word “test.” Ten days later on Sunday, the artist posted, “I didn’t mean to attack. I’m sorry.” Later that day, she was reported missing. On Monday, she was found dead by the police, with an apparent suicide note found at her home.

To piece together what happened in that brief span of time, X users are going in search of clues, treating the internet as a virtual crime scene — and appointing themselves the arbiters of law and order.

Ashihara was the creator of manga “Sexy Tanaka-san,” which has been serialized by publisher Shogakukan. The story is about Kyoko Tanaka, who works in accounting by day and as a belly dancer by night. Starting in October, a live-action TV adaptation starring Haruka Kinami ran on Nippon TV for 10 episodes.