The story is set in the early days of the 21st century where the human population has greatly decreased due to bio-terror. As a result, there are two types of human beings i.e. the new breed called Nokusu and the old breed named Kyurio. The Nokusu cannot withstand sunlight and lives at night only but they are in control of the resources, lord it over the Kyurio, have young bodies and high intelligence. On the other hand, the Kyurio are suffering due to the fight against the Nokusu and live in poverty. One day, when a Kyurio man kills a Nokusu person, this leads to economic sanctions against the Kyurio thus making the conditions tougher for them. In the midst of this, Okudera Tetsuhiko (Kamiki) aspires to join the Nokusu society despite being a Kyurio while his childhood friend Ikuta Yui (Kadowaki) hates the Nokusu and wants to resurrect her ailing hometown. Co-stars also include Furukawa Yuki, Ayata Toshiki, Mizuta Koki, Takahashi Kazuya, Moriguchi Yoko and Murakami Jun.
Before the release of the movie, the novel version of Taiyo will be published in February 2016 by KADOKAWA.