Muthumudalige Nissanka, also known by his pen name Nissh Em, is a Sri Lankan public figure and bestselling author. He is a writer, traveler, inspirationalist, and social media influencer who motivates people with messages of peace, unity, and personal growth. Nissh Em has written sixteen books, most of which are bestsellers in Sri Lanka, and he plans to release five more next year.

As the director of PothMee Publication, he focuses on Young Adult and Fiction genres, particularly Horror and Mystery. Alongside his publishing work, Nissanka is involved in various social causes through his NGO, HelpPIN . He has a significant online presence, with over 200,000 YouTube subscribers and 130,000 Facebook followers, where his posts and videos reach millions globally. He also has a passion for filmmaking and plans to bring his stories to life on screen in the near future.