Souichi Tsujii is a prominent character from Junji Ito's horror manga series 'Souichi no Noroi Nikki' (Souichi's Diary of Curses). He is a peculiar and mischievous young boy with a strong interest in the occult, often seen placing curses on those who annoy him. Souichi is known for his eccentric behavior, such as chewing on iron nails and creating voodoo dolls. Despite his oddities and dark hobbies, he is more comical and pitiable than truly evil, serving as both an antagonist and comic relief in the series.