STORY :

Shinichi Izumi seorang murid sekolah tinggi biasa yang tangan kanan terjangkit oleh parasit makhluk asing bergelar "Migi" ("kanan"). Migl ialah parasit pertama untuk menghasilkan hubungan simbiotik dengan hosnya, semasa dia dan Shinichi menjalin hubungan persahabatan begitu berat. Migi bukan satu-satu sahaja Parasit di muka bumi, namun, dan tatkala kes pembunuhan Parasit manusia mula tercetus, manusia berusaha membunuh Parasit. Shinichi dan Migi mendapati mereka tersepit antara pergelutan kuasa dua pihak terhadap planet bumi.

Shinichi Izumi is a normal high school boy whose right hand has become infected with an alien parasite that names itself "Migi" ("right"). Migi is the first parasite to develop a symbiotic relationship with its host, as he and Shinichi slowly develop a grudging friendship. Migi isn't the only Parasite on earth, however, and as cases of Parasites killing humans begin to emerge, humans seek to kill off Parasites. Shinichi and Migi find themselves caught in between these two sides of the struggle over planet earth.