Manyosen is the name for both the company operating and the line. It is a combination of Takaoka Tramway Line and Shinminatoko Line, but it is operated as a whole line. The tram connect between Takaoka and Koshinokata.
I really like the cute pictures in some Japanese trains/trams, like in the second photo in the post body. There's a Not Just Bikes video where he takes the Shinkansen, and one of them is Pokemon-themed, too. It's so cute, and it makes public transport so much prettier!