Headcanons (Koi)

Koi gets annoyed and almost downright possessive over her glasses at times. Not just because she needs them to see, but because it feels like an important part of her that she likes to have in her own control. She won't kill anyone over it- but she'll give you the nastiest look you could imagine. Now if you broke them? Then she might. 

(Incidentally, its a running gag that any innocent person that touches or moves her glasses while she sleeps is not warned when everyone else bolts before they get caught)