Kidou Senshi Gundam AGE

In Advanced Generation 101, the colony Angel is destroyed by a mysterious enemy humanity cannot identify. Seven years later, the same force attacks the colony where young Flit Asuno lives, killing his mother and leaving him an AGE Device containing plans for an ancient mobile suit called Gundam.

Flit dedicates the following years to building the AGE-1, then enters battle when the enemy reaches Nora. His fight becomes the beginning of a conflict that stretches across roughly a century and through his own descendants, Asemu and Kio. As each generation inherits both the Gundam and the consequences of the previous one's choices, humanity gradually learns that the war against its supposed unknown enemy is far more complicated than it first appeared.