Technical term in poetics and rhetoric for the repetition of vowel sounds within words or phrases, similar to English assonance.
Assonance is used effectively in the poem.
脚韻 is end rhyme, a different sound device from assonance.
Compound of 半 (half, semi-) and 諧音 (harmonious sound, euphony). The term is a Japanese-coined technical word for assonance.