You've stumbled upon the 'OthER HaLVeS'...
H: ...Yukina-chan doesn't want to call it 'PeT StoPS' or
'Our Pets'...She thinks they shouldn't be pertained to as
Y: Hiei-san, they are our persona's other
half...Actually, I wanted to call this the 'CutEY StoPS',
but Oniisan said it was too feminine for him...Well,
manni-san, here, you will get to know our Beloved Other