The Isolator, Vol. 2 (light novel)

An alien parasite living inside of Minoru Utsugi gives him the power of Isolation–an unbreakable shield that surrounds his body. With this power, he’s managed to defeat an evil Ruby Eye. Having done so, he’s invited by the Accelerator–a girl named Yumiko–to join a mysterious organization whose goal is to defend humanity from the threat of the Ruby Eyes. Minoru agrees to join, with one condition: Once he has fulfilled his duty, the syndicate will erase all memory of his existence from the world–for Minoru seeks a world without any knowledge of him, a world of total and perfect isolation.