To unlock the first and second hokages, do the following. First, select Ultimate Contest mode and complete it. Then, head to the academy and talk to Udon and Moegi, successfully completing their ten riddles. From there, go to Shushuya Restaurant. Here you will meet Ebisu. Answer his riddles like you did the earlier characters. When completed, the first and second hokages will be unlocked.
To unlock the first and second hokages, do the following. First, select Ultimate Contest mode and complete it. Then, head to the academy and talk to Udon and Moegi, successfully completing their ten riddles. From there, go to Shushuya Restaurant. Here you will meet Ebisu. Answer his riddles like you did the earlier characters. When completed, the first and second hokages will be unlocked.