Mirage Mansion

Mirage Mansion is a court in Mario Tennis Aces that takes place in a haunted house. Broken black-and-white floor, chairs, and armchairs are seen in the background. Peepas and a Big Boo serve as line judges and the court's referee, respectively. The court's gimmick is two mirrors that appear in the center; when the ball touches one, the mirrors switch sides and the ball comes out of the other mirror.

In-game description

 * "Mysterious mirrors adorn a mysterious mansion. But...where exactly does a tennis ball go when it disappears inside one of these mirrors?"

Adventure Mode
In Adventure Mode, Mirage Mansion is the third area visited. Mario and Toad come here searching for the second Power Stone. Upon arriving at the mansion, the duo are antagonized by a trio of sentient mirrors. They summon Boo, who challenges Mario to a tennis match. After that, Mario reaches the Reflection Room, where he must solve a mirror puzzle within a time limit in order to move forward. The mansion is ruled by the mirror queen Madame Mirage, who guards the Power Stone. Optionally, Mario can accept a challenge from Boo in which he needs to knock down panels with the tennis ball; if he completes it, Boo will give Mario a hint for solving the puzzle in the Reflection Room. There is also another optional mission where Mario needs to return the ball to Boo until he reaches 300 points, which will reward him with the Mirror Racket.