"Sensei, also known as Natsuki Ohtori, is a main character in the Japanese manga ""The Lady Wants to Rest"". Sensei is a middle-aged man with short black hair, glasses, and a tired expression. He is often seen smoking cigarettes and drinking alcohol.

Sensei is a former teacher who quit his job due to burnout and now works as a writer. He is well-respected in the literary world, and many of his former students idolize him. However, Sensei is haunted by his past, and he often feels guilty about his failures as a teacher.

Despite his gruff exterior, Sensei is a kind and understanding person. He takes an interest in the protagonist, Lady, and helps her overcome her anxiety and depression. Sensei also forms a close bond with Lady's son, Tomo, and becomes a father figure to him.

Throughout the manga, Sensei deals with his own personal struggles, including his relationship with his estranged daughter and his feelings of regret over his past mistakes. However, he always tries to maintain a positive outlook and help others when possible.

Overall, Sensei is a complex and well-developed character in ""The Lady Wants to Rest"". His struggles and motivations add depth to the story, and his interactions with Lady and Tomo are heartwarming and touching."