Here is a 2009 Japanese language video on the insides of the preceding Oyashio class submarine. The last of the 11 Oyashios was commissioned in 2008. They are still in service alongside the new Soryus. Oyashios are very similar to the Soryus except Oyashios don't have Stirling AIP.
The Oyashios have a crew of 70 and weight is 2,750 tonnes (surfaced) - which implies long endurance even if they don't have the long transit stages of the Collins.
Note in the video how large the work areas seem - though the sleeping areas look more cramped. Note damage control training facilities 5mins 20secs in. Many Australian Navy and submarine maintenance people will need to become much more aware of the Japanese spoken and written language.