stuff mukami azusa would probably be really into:
squishy cheeks!! a pair of pretty brown eyes and some soft, round cheeks are enough to liquidate him on the spot. loves the side of a girl's face in general; thinks they look very pretty when they rest their heads on their desks in class so he can see the smooth slope of their side profile, ears peeping out from in between locks of hair. finds it oddly innocent, and incredibly appealing
braids because he adores details. his favourite is braided natural hair, because it can be accessorized to a greater extent, but a simple set is nice too. likes the look of the hundreds of interwoven strands and often gets distracted by the shine and their twisting, serpentine manner whenever he sits behind a girl with braided hair in class (which is why he's failing history)
old scars, the ones so deep they still haven't faded - preferably on darker skin so they stand out more. thinks of them as little Easter eggs in a person's body, and anytime he comes across one he always wonders at the story of how they might have gotten it. also into veins on paper pale complexions, thinks they're vaguely erotic and that they serve as a quick reminder of the hot blood tempting him from under the skin.
pretty wrists and pale arms get him GOING, anytime he sees the curve of a girls' forearm he's just itching to whip out a knife and brutalize it until it's a pulsing, crismon mess. another thing that drives him crazy are innocent looking, loose clothes that give the appearance of such softness - until they turn towards the light and the fabric goes entirely see through
girls with gentle interests! not really into loud, volatile hobbies like thrill seeking or contemporary dance, and instead gravitates towards people who do small, quiet things that require a great attention to detail. gardening and flower arrangement, pottery making and oil painting are the gold standard for him, and he could watch someone do them for hours, captivated. will definitely ask you to stick a paintbrush in his eye. please do not oblige.