That was a very nice and dramatic final episode. I do like how things went full circle here, as Kanba-shouta and Shouma-shouta had the same conversation here as those two boys had way back in Episode 1.
Part of me would have preferred a happier end, but all-told, this was pretty good. I'll probably have more to say on this tomorrow, when I'm more well-rested.
For now, though, let me just say (somewhat jokingly
) I
called it!
Himari's "fated one" was indeed... Ringo!
Himari, by her own words, feels relaxed in Ringo's presence, and Ringo makes sure that Himari is not lonely. With the beautiful but tragic sacrifice of the brothers, there's no male to stand in the way of their inevitable bond.
Yuri end FTW! 
Sorry, but I couldn't resist, because it is a bit funny given my wild (and admittedly pretty far off) speculations of three months back.
In complete seriousness, both the Ringo/Shouma and Kanba/Himari pairs had lovely final moments together, and I'm pretty pleased with them.
I will also say that the seiyu work in this show was simply all-around fantastic, and this episode certainly showcased that nicely. I hope that the seiyu for the four main characters, as well as Sanetoshi, all get more roles soon. This anime had excellent emoting from its actors/actresses.