The Gauna Higgs particle beam cannon self- destructs causing a rupture in Sidonias armored hull. Although the risk with this hybrid technology is high, the captain wants to proceed with the research program and harness the power of this weapon at any cost. A new system which enables linking multiple Gardes, indicates a direct head on attack is approaching. Tanikaze is unaware of several love interests that are attracted to him, he especially is not aware of Izana. The colonist at planet 7 come in deadly first contact with the Massive Gauna cluster.