A character from the Rainbow Bubblegem series. A new character appearing in Season 2, he is a student at Blue Dot School and a senior to Leo and Purple's group. After the battle with the Black Curse (Phantom and Pale) at the Blue Dot Island Autumn Festival, he reveals his true identity and confesses his past to Leo and Purple's group. His true identity is the prince of an ancient mermaid marine kingdom that disappeared long ago. After waking up from being trapped in a glacier for a long time, Gray found that his homeland was already gone. He came to Blue Dot Village to find clues related to mermaid legends. While following the location of the mystery of the ancient mermaid kingdom depicted on a scroll Purple's group found in the Jellyfish Kingdom, Purple becomes suspicious and follows him. Gray eventually confides his secret to Purple. The two ride the oldest sea turtle to find the location of the ancient kingdom's mystery and eventually succeed. At that moment, the Black Curse blocks and attacks them, but Dark suddenly stops Phantom and Pale's attack. While the sea turtle blocks the cave, the two finally see the ruined ancient mermaid kingdom and suddenly burst into tears. After they stop crying and take a rest, Gray's true past is revealed. As the prince of the ancient mermaid kingdom, Gray once received a warning that a glacier was drifting toward them. He tried to stop the glacier with his brother and his people, but it was too heavy to block. Sensing that someone had dragged the glacier from the opposite direction, Gray told his brother he would check below. Upon heading down, someone attacked him, causing him to hit the iceberg and lose consciousness. Subsequently, the ancient mermaid kingdom was destroyed. While sleeping in the ice for a long time, he was cursed by the one who attacked him due to his desperate desire to find his brother, and he eventually woke up. The culprit who attacked and cursed Gray was none other than Black Diamond. Under Black Diamond's curse, Gray eventually transforms into Dark Gray, leaving Purple in shock. He is one year older than the seven princesses (15 years old).