Daisuke S.
Google
The souvenir shop is on the first floor, so you enter through a small entrance at ground floor.
The store is quite large and has almost every type of souvenir.
All the products have price tags and are reasonably priced.
Best of all, you can take your time looking around without being bothered by the store staff. There's no price negotiation or rushing, so you can look around as many times as you like.