A story that revolves around three sisters who live in their grandmother’s home and the arrival of their 13-year-old half sister.

In an alternate Japan, territorial street gangs form opposing factions collectively known as the Tokyo Tribes. The simmering tension between them is about to boil over into all-out war.

By the year 2050 AD, a mysterious organization called Galactor has occupied half of the Earth and threatens to exterminate the human race. Around the same time, the International Science…