 If you liked Gantz |  ...then you might like Kaijuu 8-gou |
Gantz and Kaiju #8 share some similarities with their general premise: -Monster tech in the form of power suits and weapons = Alien tech in the form of power suits and weapons. -Overwhelmingly powerful monsters that are large-scale threats = Overwhelmingly powerful aliens that are large-scale threats. -MC has a childhood friend who he wants to be like and stand alongside = MC has a childhood friend who he eventually wants to be like and stand alongside. -MC can't risk revealing his secret power = MC can't risk revealing his secret alien hunting sprees.
report Recommended by Captainjeddy
Both series focus on humanity's mission of fighting against Monsters/Aliens to avoid total annihilation. In both series, humanity develops technology with resources belonging to the Monsters/Aliens, In the case of Gantz humans create weapons from Alien tech whereas in Kaijuu no. 8 humans created weapons from Kaijuu. In Both series, humans wear special suits that increase their natural capabilities to inhuman levels. Main Character has a childhood Friend/Rival - Mina Ashiro for Kafka Hibino and Masaru Kato for Kei Kurono.