Like the British equivalent, the JR2 - Japanese Heavy Weapons code from Heroics & Ros consists of a Command strip with 3 Mortar strips and 3 MG strips.
Click the images for a more detailed view.
2-man light mortar team, 3-man medium mortar team, 4-man infantry gun team (Type 11?)
Prone LMG gunner, 3-man tripod-mounted HMG team, and an AA MG gunner.
I'm not 100% of the actual types here.
Mainly Officer types.