The fans really want to meet the real person behind this VTuber.
Tips
history
In Kantian philosophy 本体 is the standard translation of 'noumenon' — the unknowable 'thing-in-itself' opposed to 现象 (xiànxiàng, phenomenon). The everyday Chinese sense ('main part, the thing itself') predates this loan.
usage
Modern internet usage: VTuber and virtual-idol fans use 本体 to mean 'the real human animating the avatar.' E.g. 找本体 = 'figure out who the real person is.'
