I am simplifying it and ignoring the parent's stories, but both focus on supporting a child through her illness and coming closer as a family to do so. While the parentage isn't that complicated in Wonder Life and after the diagnosis of the daughter Han Shin Bi, the focus shifts from a love story to focus on family. If you want more of an emotional roller coaster, I would say watch Oh My Geum Bi. Both even have Lee Ji Hoon! Both are worth watching and shedding a few tears.