There are some new additions joining the roster in Mario Tennis Aces, as Petey Piranha and Shy Guy are expected to make an appearance in the game sometime next month. However, it won't be easy to unlock them and players hoping to grab these new characters will have to draw on all of their tennis skills to do so. In fact, players will have the opportunity to unlock the two characters by competing in online tournaments from December 1st through to December 31st, in singles (to unlock Petey) or in doubles (to unlock Timid Type).
If you haven't got the skills to unlock them in the month of December then no problem, as both Petey and Shy Guy will be both available to everyone starting from January 1, 2019. In the same period, Pauline, Luma and Boom Boom will also be available in the game, as previously reported.