Rintenshiki Stereopticon: jailed in 2002

It's something like a typical sci-fi story that pretends to be a story of love and courage that pretends to be a bright and cheerful buddy action story set in the near future, which in the end is surely a story of love and such things— the girl with flowing silver hair says with a laugh. On June 5, 2002, a part of the city called Tokyo suddenly disappeared. This is a near-future buddy action story between Takumu Azekura, a mediator who solves troubles between earthlings and aliens, and a strange silver-haired visitor called Melinoë. (Source: Kadokawa, translated)