Hello, Good-bye is Lump of Sugar's fifth (sixth if including the sequel of Tayutama: Kiss on my Deity) visual novel produced. It was officially released on October 16th 2010.
In a distant Japan, civil unrest has divided the country into two conflicting governing factions, United provinces of Japan and Japan Federation. As weapons develop, the damage only worsens on the country as a whole. Thus the leader of the two parties agreed to a ceasefire treaty. The treaty, declared on the area Morino, was then named Morino Ceasefire Treaty and has been honored for a hundred years. Toubu Kaito, or rather the agent undercover, is to infiltrate the neutral grounds Morino and gather intelligence for the United provinces of Japan. Upon arrival, he reports to his school first, Tenshudo Academy. Notified that registration will be tomorrow, he wanders around town to get familiar with the landscape. He ends up at the Morino peace memorial park where he meets a girl. “Good afternoon. Or rather 'nice to meet you'…hmm I guess technically speaking it should be 'Good evening'? My name is Yukishiro May, how do you do. And you are?” Taken aback by May’s smile, the agent slipped the “truth” through his words: “Toubu…Kaito. At least while I am here.” Little does he know that this reply would change his fate forever.