Well, as long as i know. You just can't make him to sound more realistic with just a simple click in some magic pluggin xd
you have to know how to manipulate pitchbends, dynamics and a lot of stuffs so xd i'm not trying to being rude xd i'm just answering this :B
oh well xd my Vocaloid pitchbends are not pretty cool but they're in UTAU so i export the vsqx as a vsq and then import that in UTAU and do my kawaii (awful) pitchbending and then export that as a midi and then put that in Vocaloid (?
i hope that make sense xd