TOKYO — The recent death of Hana Kimura, a bubbly, pink-haired 22-year-old wrestler and reality TV show star, has spotlighted a rise in cyber bullying in Japan and prompted swift official pledges to do more to protect victims.Kimura, a cast member on the popular program Terrace House, was found dead at her home on May 23 from an apparent suicide after being deluged with negative comments on her social media feeds.Acutely aware of the public debate spurred by her death, Japan’s ruling party is holding hearings from this week to consider legal changes that will help cyber bullying victims seek justice. “People must understand where the line between constructive criticism and abuse lies,” Junko Mihara, a member of the ruling Liberal