Yakui is addicted to pharmaceuticals. She's known to give out medicinal advice to passersby in drug stores, but whether this advice is good or not is up for speculation. At critical moments, she can see what is invisible to others and hear what others can't hear. She's very capable without her medication, but a slight overdose would make her useless. The handcuffs are meant to force her to cut down on her medication every month to behave.