That makes sense. Like if Hinako shows that she cared and was scared, maybe it would prove to Miko that Hinako doesn’t want to die, which is what Miko wants in the end. Same as Shioriko. But if she’s so lackadaisical about it then Miko might think Hinako isn’t being genuine about wanting to live.I think one problem might be that Miko wants Hinako to care. Not being worried that her best friend was a monster that brutally mauled humans to death would suggest that her suicidal thoughts are so strong they're overwhelming her sense of morality. Hence Miko is now in a Scylla and Charibdis situation where, if her past is revealed, Hinako would either have to abandon her or abandon humanity. At least this would be the problem as Miko perceived it.