The flowers that wash up on shore in tsunamis that we make into syrup is seaweed. Okay, so it's more like soup or tea than syrup, but you can make them both out of seaweed.
Seaweed is true soul (そう) food. Which means it's good for your soul. Didn't you ever read those books about chicken soup being good for your soul? Well that was a lie. Miso soup with seaweed is what's really good for your soul.
Currently there are no similar looking kanji which exist in the WaniKani learning system