Well, just from the first sentence of the review, I guess I need to see this one whenever that becomes possible.
Mari Okada has been ridiculously hit-or-miss for me; Anthem of the Heart is literally my favorite movie, and I liked Nagi no Asukara (that one with the mer-people who look exactly like normal humans), but I couldn't stand Hanasaku Iroha (it felt like an ode to Japanese workaholism) and had mixed feelings about Anohana (Menma's "ghost" is so similar to a living human that she's effectively not dead, just invisible to most people; this turned most of the drama into melodrama). But this one seems like it could be good. It does mainly remind me of Aragorn and Arwen, as someone else pointed out, though apparently it's not a romance.
...I'm going to stop there because something on this site is randomly scrolling the page up and down, it's driving me nuts.