Yeah, nothing would change if you didn't let a random person randomly saying rude and random shit bother you. But we all know you will, so I guess things will change. Hooray.
"Get away from her," she says. "Who are you?" I ask.
This is one of those moments I should be annoyed at the new character but I'm more annoyed that our MCs are acting like any random person will cause them to instantly crumble. Now we're even accepting that she'll come again to "reassess us"? For what exactly? She's younger than you, you're her senpai and you don't know her. "What if she thinks I'm only getting in Nagisa's way?" Who cares? This should be a nonstarter.