Winter Palace

The Winter Palace is one of four rooms in Issei Tenkai's mansion connected to the fountain patio. From the entrance to the patio, it is the second room from the right. All four rooms contain a stream of water that leads to the fountain in the patio.

In 2000, during Tenkai's confectionery design competition, it was assigned to Delicy Scone for building her entry for the finals. However, Isaku Hyōdō, one of the other contestants, was murdered, and his entry, consisting of frozen sherbet sculptures of the signs of the zodiac, went missing. Tenkai was arrested and convicted for the murder. Over 18 years later, Tsukasa Oyashiki, Tenkai's adopted daughter, opened the Zodiac Art Gallery inside the mansion, claiming to have replicas of Hyōdō's sculptures. The Winter Palace was where the sculptures representing the signs of the winter months were displayed.

The false cream castle

 * Main article: IS-7 Incident

When Tenkai's parents died, he inherited his father's company, the Tenkai Group, as well as the "Angel's Recipe", a book containing procedures for experimental pharmaceutical drugs. When Tenkai announced the highly sought-after book as the grand prize for his design competition, the Tenkai Group sent one of their own, Delicy Scone, in an attempt to win it back. With the help of Tsukasa Oyashiki, Scone built a cream castle. In reality, the castle was mostly made of inedible material, essentially a mannequin that was merely covered in cream. Moreover, she used inedible props such as glowing cloths and rock salt lamps, which were against the rules. Subsequently, her entry was disqualified; Tenkai confiscated the lamps and cloths, and kept them in his room.

Some time later, an altercation occurred between Yutaka Kazami and Hyōdō in Tenkai's room, in which they hit each other with the lamps, resulting in the latter's death. Thinking to frame Scone for the murder, Kazami removed his own blood from one of the lamps, leaving Hyōdō's bloodstain on the other. He then hid the lamps and cloths inside Scone's castle, where the police would find them, though one of the cloths was placed over the body to help incriminate her further. However, Tenkai was arrested instead due to Hyōdō's body being discovered in his room.

Prosecutor Manfred von Karma and Detective Tyrell Badd were placed in charge of the police investigation, with Tenkai's lawyer, Gregory Edgeworth, arriving soon after the investigation had started. It was in Scone's room that Edgeworth and von Karma first met, with the latter addressing the former condescendingly before leaving to investigate Kazami's room. Because Scone set the temperature controls in the room to room temperature, the cream castle began to melt, exposing it as a fake.