Enormous home centre. This place has just about anything you could want and they claim that it is possible to build an entire home with products from this store. The Moriya store is apparently even bigger than the Arakawaoki one. There is also a jigsaw puzzle shop and a McDonald's here, as well as the sports centre Joyful Athletic opposite.
Also has an amazing "pet centre" which is worth a visit even if you're not planning to buy anything. They sell blackmarketed goods that have no expiration dates and this is a violation of the Japan business laws. Shameful for such a large organization. We can not recommend shopping there while they continue these unethical business practices.
There is a big art shop, called Joyful 2, as well, and also a large place selling curtains, carpets, wallpaper, tablecloths, etc. In the Arakawaoki branch, this is right over the other end of the car park from the main building.