Anyway, in Akiha's normal ending, Akiha succumbs to her inversion impulse, and becomes an emotionless, primitive, beast-like creature that acts only on instinct. She is isolated in the detached building, and Shiki ends up taking care of her, visiting her frequently, letting her leech and feed off of his blood, tending to her needs, etc. Similar to the reed warbler which raises another bird's offspring, Shiki raises/cares for/tends to a creature who mentally isn't the person that he has come to love. They both care for something that they really aren't inclined to care for, and they both are victims of another parasitic creature. In a metaphorical sense, Shiki is a "Distant Reed Warbler" and Akiha is the cuckoo.
I just thought that I'd share my opinion on how clever the ending's title is. Akiha's normal ending just really left an impression on me, probably because of its depth and meaningful title, but mostly because of the fact that Shiki strives to maintain his smile for Akiha, so that she can return to sanity never seeing his sad face.