Mei Hoshino, a kind and soft-spoken high school student, leads the writing club. She has light-green hair styled in braids, wears glasses, and is typically seen in her school uniform, often with a book-shaped hair decoration on the left side of her head. She actively encourages club members in their writing and offers compliments on their stories, demonstrating respect for creative efforts. This is evident when she intervenes to correct Saki's rudeness toward Yumeji's story, emphasizing that constructive feedback is acceptable but outright criticism is not.

Mei's primary narrative involvement centers on her relationship with the dream demon Chris Evergreen. Initially believing Chris is a human pen-pal who contacted her accidentally via text, she grows close through their exchanges and eventually expresses a desire to meet him. Unbeknownst to her, Chris manipulated this connection by using Mei's own secondary cellphone to communicate, facilitating his plan to possess her as a vessel. After Merry Nightmare intervenes and sends Chris back to the Dream World, Mei loses most of her conscious recollection of him. However, fragmented, lingering traces of their interactions subtly influence her writing and creative expression afterward.