Gigant Vol. 7 (manga)

The horrifying giant that laid waste to America has turned its sights on Japan, and as the titan draws close to Tokyo, suicide rates go through the roof. Somehow, the monster is driving people into unnatural, self-destructive despair. Separated from her boyfriend after their relationship became a national scandal, Chiho gets some unexpected assistance: a group of time travelers from the distant future, who know the truth behind all the bizarre disasters threatening the survival of the human race.