Mecha Ude: Mechanical Arms

Long ago, extraterrestrial lifeforms arrived on Earth and began fusing with humans. Because their merged forms closely resembled mechanized limbs, they became known as "Mecha-ude." Hikaru Amatsuga, an ordinary middle school student, finds his life forever changed when he is thrust into an involuntary partnership with Arma, a remarkably rare and unique Mecha-ude. To safeguard Arma, the resistance faction ARMS assigns Aki Murasame, a skilled dual Mecha-ude user, to shadow Hikaru at all times. Yet Aki carries her own hidden agenda: she is relentlessly hunting a mysterious Snake-Type Mecha-ude wielder responsible for leaving many of her comrades in critical condition. Operating covertly, the powerful Kagami Group scours the world for the legendary "Trigger Arm," a mythical Mecha-ude rumored to bestow limitless power upon its user. When the organization's dangerous ambitions put Aki's life in immediate peril, Hikaru can no longer remain a passive bystander. Forced to unite with Arma and summon his courage to fight back, he soon realizes that his days of living a normal life are over, and that this extraordinary alliance will shape his destiny forever.