Talk:Izuna Hatsuse/@comment-173.89.175.198-20140809015647/@comment-173.89.175.198-20140810215030

Desu is just a polite version of  da. It always means "is" or "am". It is similar to adding the "O"  in front of otou-san, or onee-san instead of just saying tou-san, nee-san.