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> Rendaku (?, lit. "sequential voicing") is a phenomenon in Japanese morphophonology that governs the voicing of the initial consonant of the non-initial portion of a compound or prefixed word. In modern Japanese, rendaku is common but at times unpredictable, with certain words unaffected by it.
_Rendaku_ is the changing of voicing that, in practice, is usually the addition of a _dakuten/tenten_ to the first syllable of a word contained within a compound or phrase.
As mentioned above; rendaku occurs commonly but is unpredictable, in that there isn't any fit-all rule that determines when it applies. However, rendaku commonly appears in words involving the _noma_ iteration mark () indicating repetition of the prior character, such as in _hitobito [/, not hitohito]_ and _samazama [/, not samasama]_
In your example, __ is considered a single phrase in that __ is a modifier describing __.