There are several Toysrus in Yokohama (store list)
And Toysrus Japan has point (membership) card system. We found that they have the application form in English. The membership is free of charge and we can get 1 point per 200 yen (of purchase). They have also "bonus points" or "double ~ ten times points promotion" systems from time to time. And when the point reaches 500, we can use it as 500 yen at Toysrus.
There are also sales only for card holders (for example, a toy was ¥999 for card holders while it was ¥1,399 for non-holders the other day).
You can ask for the card at the cash desk.
This is the application form in Japanese.
This is the one in English and the card.
Once you become the member, you can check your points or change your account information online.
Here is the Toysrus member page guide (opens a new window) .