the quadruplet male cubs were let out into their glass cages for the first time at the tobu zoo in saitama prefecture , on the outskirts of tokyo .
initially hesitant to go out in front of a crowd of zoo staff and visitors .
it took two kitties at least three attempts to finally manage to pull out their loudly complaining brother .
` we can hear it from beyond this glass wall , it must be screaming really loudly .