In many of the convenience stores in Taiwan, you can get seals when you buy certain amount of shopping.
You can exchange limited character items with the collected seal.
You collect the seal..、
You can get this kind of item. But it takes a time. and there is a expiration date.
If you want this kind of limited item, you can buy website auction or shop at Taipei station underground mall.
it costs about 150NT$.
They are located in the back of the Taipei Main Station underground shopping mall.
They are sold in the case like this.
Most of them are limited items.
I think they are good for Souvenirs.
Taipei City mall
100, Taipei City, Zhongzheng District, Section 1, Civic Blvd