Hitotose Chitose is now living together with his 5 teachers as his mothers when a mysterious girl appears and becomes their neighbor which turns out that that person is Nagatsuki Kuron who wants Mu-chan to be her mother so another sibling rivalry ensues as to who would end up as Mu-chan's child. (Source: ANN)

The three brothers discover that the human experiment banned after destroying the Orochi, is still going on to secretly revive the evil snake. They also find out that some ex-members of the Yamainu (the Japanese military unit formed to kill the snake) are behind this conspiracy. The brothers fight together again in a battle against the military. (Source: Amazon Prime Video)

A comet burns in the sky, its brilliant light shining down upon the people of Earth. At that time, a giant army of viruses invade the real world, crushing everything in their path. Netto and Enzan use cross fusion to intervene, but are whisked away to an unknown location, only to be confronted by the one responsible for the attack - Duo! (Source: Official Site)

Second season of Hanazakari no Kimitachi e.