In this 2020 anime series, high school student Shuichi Kagaya gains the ability to transform into a giant dog mascot costume, and with Clair Aoki, seeks answers about a mysterious alien and collectible coins. Name the show.

The anime series described, where high school student Shuichi Kagaya can transform into a giant dog mascot costume and teams up with Clair Aoki to find answers about a mysterious alien and collectible coins, is titled Gleipnir. This 2020 dark fantasy and supernatural (Review) thriller follows Shuichi's bizarre transformation and his reluctant partnership with Clair, who quickly discovers the unique secret of his monster form: a zipper on his back that allows her to literally enter and control him. This unusual symbiosis grants them enhanced abilities as they navigate a dangerous world filled with other individuals who have also gained powers.

The central mystery of Gleipnir (Review) revolves around an alien who crashed on Earth, scattering his comrades, who took the form of collectible coins. This alien, often found residing in a vending machine, grants wishes to those who bring him coins, leading to a deadly "coin hunt" where powerful individuals, known as "gatherers" or "collectors," battle each other to collect more. Shuichi and Clair become entangled in this high-stakes game as Clair seeks to uncover the truth behind her family's murder, which she believes is connected to her older sister, Elena, and the monstrous transformations.

The series delves into themes of trauma, morality, and the blurred lines between humanity and monstrosity. Shuichi, initially a timid boy, struggles with his new powers and the violent world he's thrust into, while Clair, despite her manipulative tendencies, develops a strong, albeit complex, bond with him. Their journey to gather coins and confront the alien ultimately leads them to unravel painful pasts and confront the dark desires that drive both themselves and other supernaturally gifted individuals.