It looks like the Japanese Office 2010 font list is the following (all by RICOH):
- HGGothicE
- HGGothicM Medium
- HGGyoshotai Medium
- HGKyokashotai Medium
- HGMaruGothicMPRO
- HGMinchoB Bold
- HGMinchoE
- HGPGothicE
- HGPGothicM Medium
- HGPGyoshotai Medium
- HGPKyokashotai Medium
- HGPMinchoB Bold
- HGPMinchoE
- HGPSoeiKakugothicUB
- HGPSoeiKakupoptai
- HGPSoeiPresence EB Extra-Bold
- HGSeikaishotaiPRO
- HGSGothicE
- HGSGothicM Medium
- HGSGyoshotai Medium
- HGSKyokashotai Medium
- HGSMinchoB Bold
- HGSMinchoE
- HGSoeiKakugothicUB
- HGSoeiKakupoptai
- HGSoeiPresenceE Extra-Bold
- HGSSoeiKakugothicUB
- HGSSoeiKakupoptai
- HGSSoeiPresence EB Extra-Bold