The Seoul Museum Association (SMA) made a new plan for the 2013 Museum Week events using the Internet and gamification techniques. The organization formed a network of 24 museums in Seoul as a single group on the Internet, and encouraged visitors to solve 24 missions at 24 venues during seven days (18th-24th May 2013). This system was established based on the seven gamification components set by Zichermann from the stage of design. This paper shows that this new concept of museum network brought many positive results. Over 1,000 people visited the museums in network and 53 people visited more than five museums, even though the participating museums were scattered all over the city. In addition, we collected over 1,000 stories from the visitors to the museums that provided players a special memory of museums in Seoul during Museum Week. Over 70% of the participating museums, moreover, wanted to use this gaming system in the future.