The title would appear to be that of a Japanese novel, "The Decay of the Angel", published in the early 1970s. It references the Buddhist concept of "Devas" or "mortal angels". In Buddhist scriptures, the 5 signs of the decay of an angel are:
1. The flowery crown withers, 2. Sweat pours from the armpits, 3. The robe is soiled, 4. They lose self-awareness, or become dissatisfied with their station, and 5. The body becomes fetid or ceases to give off light, or the eyelids tremble.
1. The flowery crown withers, 2. Sweat pours from the armpits, 3. The robe is soiled, 4. They lose self-awareness, or become dissatisfied with their station, and 5. The body becomes fetid or ceases to give off light, or the eyelids tremble.