Himeka Tatsugami (辰神姫香, Tatsugami Himeka) is one of the three main protagonists for Durarara!! SH.
She wears the Raira Academy's girls' uniform, which consists of a white button-up blouse, blue skirt, and a red ribbon. She has long, black hair, with her bangs somewhat hanging down in front of her face and a sidetail which has a decoration latched on to it.
She is the second born of three sisters. After her older sister goes missing during a report on the Headless Rider, she moves to Ikebukuro to search for them.
Tatsugami was first seen giving her introduction to the first year students of Raira Academy with a quiet yet clear tone of voice. Appearing generally disinterested in the class introduction, what managed to catch her attention though, was Yahiro Mizuchi's interest with the Headless Rider. After class ended that day she asked Yahiro if he was serious about meeting the Black Rider and warned him not to pursue for an unknown reason. As she turned to walk away Yahiro instinctively grabbed the back of her collar and yanked her back, choking her. She didn't get upset, only surprised that he would exude such force on her for not giving a solid reasoning behind her warning. Asking for the boy's reasoning behind searching for the rider, she realized he wasn't going to give an answer as to why. So she proposed if he would tell her his reasoning for wanting to meet the Headless Rider she would give her reason as to why he should stay away from it. She then fixed her collar and on her way out she apologized to the male, saying she didn't mean to scare him she only meant to warn him.
The next day Tatsugami met with Yahiro and they continued their conversation. Yahiro told her his reasoning for wanting to meet the Headless Rider and about his past of being called a monster. Himeka was surprised but believed him due to the fact his tone didn't sound like a lie and given that his hands were badly roughed up. She then gave him her reasoning to avoid the Rider at all costs. She told him both her older and younger sister were kidnapped by the rider after preparing to meet it later that day. Yahiro, remembering his conversation with Akane, asks if she has any relation to Tatsugami Ai. Himeka is surprised but she confirms that Ai is her younger sister. This is when Kuon Kotonami comes up the the group and joins in the conversation confirming that he and Yahiro spoke with Akane yesterday. Himeka continues to warn them to stay away from the Black Rider and that she appreciates them wanting to help find her siblings. As she turns to leave she tells Yahiro that if he wants to meet someone who can help him reconcile his past he should pursue Shizuo Heiwajima, saying "The Headless Rider is a cruel demon."
- Himeka Tatsugami's name most likely originated from Tatsuko Hime (Japanese tale), who became a dragon and guardian of the Lake Takazawa.