Just before Christmas, a trip to Nintendo Co.'s flagship store in Tokyo would have required an hour's wait just to get in and buy a plush Mario toy or a set of chopsticks bearing Luigi's face.

Opened in November on the sixth floor of the renovated Shibuya Parco shopping mall, the constantly packed 300-sq.-meter showcase exhibits the appeal of Nintendo's intellectual property contrasted against the conservatism that leads it to habitually underestimate its popularity.

The long lines are a sign of the customer loyalty Nintendo's counting on in 2020 as it ramps up mobile efforts and ponders successors for the aging Switch.