Is okay
1/4 of book story side
Here we see something interesting. The love between our two protagonists dwindles--it exists, but we see clearly the concept that love is a tentative thing, has no basis in the world of infinity. Rather, love exists and can be replaced with a new love; there is no constancy, all that exists is replacement. Nana must choose between the up-and-coming Takeuchi or Yano, the former of which is conflicted yet resolute, the latter willing to change.
The same thought, repeated again and again, that memories delusory and the present is all that exists--is again repeated here. Before, it is between Yano and Nana--now it is between Yano, sister, and Nana-san. He must--we are told--let go of his memories of Nana-san, realize that her death is real; that there is nothing left. But is this the right option?
The book concludes on a cliff-hanger.
The concluding story gives Takeuchi more character. He is, of course, from the start, pretty much exactly what this story describes him as; he is someone who self-sacrifices his love for others. His "kind eyes" are precisely kind because of this, because of his first love--love lost, turned into a memory. I suppose it is meant to deepen the meaning behind his desire for Nana, on a metatextual level, as well as provide a cute little story, complete with a poem.