The dialogue "New Kojin beast tribe daily quests are now available from Zukin at Tamamizu." is supposed to refer to new quests being added to the pool of daily quests. (that is, however, not the case either)

When you get additional quests for the day, it says "Furthermore, you will be able to undertake three additional quests from Zukin as a reputation bonus. This bonus is available until the daily reset time for beast tribe quests." and "These additional quests will become available after accepting all current daily quests from Zukin. Please be advised that you cannot undertake these quests if you have no remaining allowances."