Wow so many people misunderstanding that last page. It's not Yandere and its not a lead into some kind of Violence. She's realizing she loves Mimika and she's deathly scared now as she's slowly realizing it. She's scared about what the feeling inside her means (keep in mind this girl hardly understand what the word "love" even means). If you suddenly had an emotion that you never realize you had, you'd be scared about what's going inside yourself as well.
Also in the previous chapter we see her (Yuzumori) relationship with her mother (parents?), she probably scared of Mimika abandoning her, there is obviously no REAL reason for this fear but its still exist. The more she loves Mimika the worse this fear gets too, and that make it doubly scary.
P.S, sorry if my grammar or ortography suck at times, not native english speaker err writer.
