After taking full control of Inori's body, Mana greets Shu but is shunned by him after she speaks ill of Inori, much to her anger, and she lets Gai draw her void to fight him while she triggers the Fourth Apocalipse, spreading the Lost Christmas phenomena throughout the entire world. Haruka confronts Shuichiro who injects the Apocalipse virus in himself and his body starts cristalizing.
Kurosu Ouma is both Shu and Mana's father. After the death of his wife Saeko Shijou, he married Haruka.
A genius, he was the scientist who discovered Void Genome to be an inhibitor of Apocalypse Virus. Together with Shuichiro Keido, his friend and fellow scientist, he led the research about the Apocalypse Virus. 5 years after living with his family in Oshima, a meteorite feel down and Kurosu and his team began to investigate, the meteorite pieces had the virus cells it was Mana, who found it. After a while Yuu, a envoy from Da'ath, came and warned Kurosu and Keido about the fouth apocalypse. When Saeko gave birth to Shu, she died. Kurosu needed to protect Shu because Mana already had chosen her Adam, his blood would set the standard of the next generation.
After a long time, Kurosu started to know Haruka, he had left Shu and Mana on Oshima to immerse himself on his research. He and Haruka got married and in that year they tried to have their first Christmas together. On 24th December 2029, got caught in his research and he met Keido there, he found out that Kurosu have finally solved the mysteries of evolution and natural section. After Keido request to work together with Kurosu again, Kurosu ended up refusing, which left Keido mad and made him shot him.