Some characters involved in college tuition case (4)
I believe the answer is:
etui
'case' is the definition.
(case for needlework equipment)
'some characters involved in college tuition' is the wordplay.
'some characters involved in' says the answer is hidden in the clue (some letters in the clue).
'ETUI' is hidden in the letters of 'college tuition'.
(Other definitions for etui that I've seen before include "box" , "Small case for sewing accessories" , "Ornamental ladies' bag for small articles" , "Small case for needles, cosmetics, etc" , "a seamstress requires?" .)