Beginning greeting in Hawaii, but with slight shift of character? (5)

I believe the answer is:
alpha
'beginning' is the definition.
(alpha is a kind of beginning)
'greeting in hawaii but with slight shift of character?' is the wordplay.
I cannot quite see how this works, but
'hawaii' could be 'ha' (abbreviation for Hawaii) and 'ha' is present in the answer.
'character?' could be 'p' and 'p' is located in the answer.
The remaining letters 'al' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for alpha that I've seen before include "high mark" , "European character" , "Most prominent star" , "Greek vowel" , "starter" .)
