The direct answer is No. The government of Nepal doesn’t allow solo travelers into Manaslu region, just even for trekking. It is a requirement that there should be at least two persons to trek into this region or climb the summit. Furthermore, you will need to trek and climb with a licensed guide and crew members only. A professional guide will help guide in route navigation and they are really helpful during emergencies. Your porter will carry the baggage for you thus allowing you to enjoy the long walks without much burden on your back.