Unbeknownst to the general public, aliens coexist with humans on Earth. They came from various stars, some to enjoy sightseeing, while others deciding to live here. However, thing doesn’t go smoothly all the time and problems arise every now and then. A secret organization exists to solve these alien-caused problems: ‘Men in Black’ (MIB).

One day, an UFO tried to abduct Subaru as he walked home from school. His classmate Yukano saved him from danger and afterwards, he helped her fight off the UFO. Since he witnessed an UFO with his own eyes, she told him that his memory must be wiped. But after some twists and turns, he was brought instead to the headquarters of the MIB, which Yukano was a part of. There he saw many strange aliens and after being given a tour of the facilities, he was enlisted into the MIB. His normal life instantly turned into a supernormal one.