If you really only want to go to Tokyu Hands there are stores in Funabashi and Kashiwa in Chiba. The latter inside the station. And also one in Tokyo station. The Chiba locations will be a cheaper train ride but not necessarily quicker. Although probably more frequency in the timetable than NEX.

Otherwise, check to see if you can buy the product online at Rakuten. Should be quick and cheap to ship to Taiwan.

There is also shopping around Narita city. A large Aeon mall on the north side and I have driven to a lot of strip mall stores south of the city. But it is not close to the train station.