Goto Niri has a very strange twin older sister. She rarely speaks, but often does very odd things. Since she has no friends at all, she shuts herself away in her own little world, and she seems to have delusions of persecution, too. Poor thing. Ah, just thinking about it makes me want to shed pearls (fake crying).
Goto Hitori: I feel like I can go outside as long as I hide behind you, Niri! I'm so sorry, but please just let me stay here forever!
Goto Niri: You're a family parasite, Sis.
Goto Hitori: Hello, everyone. I'm Goto Hitori, the family parasite, desu...
P.S. Bocchi the Rock! fan fiction