As of 12th April the Custom ISO for Hitachi Servers has been uploaded to the myvmware.com.
You will see there are three vendors right now who have produced custom ISOs. Of the major vendors Hitachi and HP are two of the names listed, which demonstrates the ongoing engineering effort being committed to ensure Hitachi systems are capable of leveraging new vSphere features as they are launched. This has been borne out in other areas where we are now one of the first vendors to support new features. This is also the case with VMware VVol technology.
For any customers using our blades or rack servers you may also refer to THIS PAGE for a further breakdown of drivers and components.
Enjoy vSphere 6 !!