the thing abt mitya is that he does have natural & refreshing aegyo but hes too aware of this fact. so he dials it up to an artificial level to try and get what he wants which backfires with everyone who actually knows him
after coming face to face with death, he fished out his unfinished will (or letter home as he calls it because he's writing to his parents anyway) and wrote of how life is treating him well while thinking of his friends.. oh mitya may you never lose your spark :(