Yoshiki Tsujinaka is one of the main protagonists in the manga series 'Hikaru ga Shinda Natsu.' He is a high school student and best friend of Hikaru. After a tragic accident, Yoshiki becomes deeply involved in the mysterious events surrounding Hikaru, experiencing a blend of psychological horror and emotional turmoil. Yoshiki’s character is defined by his loyalty, sensitivity, and growing suspicion about Hikaru’s true identity, making him central to the unfolding suspense and drama in the story.