Fafner In The Azure Vol. 5

Life for Kazuki Makabe is relatively normal – until he discovers that most of the world has been destroyed by aliens and his island home is only around because of an advanced cloaking device. After the island is discovered by one of the aliens, a chaotic turn of events throws Kazuki into the seat of a mecha called a Fafner, a last line of defense for his people.
Notice: This manga is written in Japanese.