My son dislikes celery, but he mistook this as simmered fuki and ate a ton, saying it was really tasty. Because it's simmered until it softens, you won't taste the celery's fiber at all. Japanese-style celery is actually quite good.
Adjust the amount of kombu tea since its saltiness really depends on the brand. I didn't add any soy sauce to keep the celery's nice color, but you can also add some for flavor.