Japantown is a few blocks with the Hotel Kabuki and Japan Center being the heart of it. The East Mall has great Japanese souvenirs and authentic Japanese restaurants. It’s a good place to go when it’s raining since it’s all indoors.
There’s also a place called Pika Pika where you can take photos at a photo machine and dress them up. I haven’t done this since I was a college student visiting Seoul. The machines now take even better photos and it’s even more fun to decorate them.