Upon arriving at the train station of death, an impure soul is granted a second chance at life against his will. Reincarnating into the body of Makoto Kobayashi, a 14-year-old boy who recently committed suicide, the soul is tasked to identify the boy's greatest sin in life within a time limit of six months. Although it remains reluctant toward continuing life as Makoto, the soul soon begins to notice the complexities of people's emotions and actions. Deconstructing the ideas of fractured families and suicide, Colorful explores the intricacies of the daily struggles humans face but are too abashed to confront.

Aileen Lauren Dautriche's life changes forever on the day her engagement with the crown prince Cedric Jeanne Elmir is nullified so he can be together with Lilia Rainworth. The event triggers Aileen's memories from her past life—she has been reincarnated in an otome game as the villainess, who is destined to die in the final act. To prevent her predetermined demise, Aileen has only one option: to court the game's last boss, Claude Jeanne Elmir—the proclaimed Demon King and Cedric's half-brother—and marry him. However, it is easier said than done, as Claude distrusts her intentions. Instead of giving up, Aileen adamantly tries to win his heart by helping Claude fulfill his wish: to build peace between humankind and demonic beasts. But time is running out, and it is up to Aileen to change the course of not only her tragic ending but Claude's as well.

Angelise Ikaruga Misurugi is the first princess of the noble Misurugi Empire. The kingdom has seen great power and prosperity due to the advancement of the revolutionary technology known as Mana, an abstract bending of light that has reduced the world's problems of war and pollution to a timeless peace. However, not all are blessed with the ability to wield Mana. Those who cannot are labeled Norma, outcasts of society who are considered a threat to civilization and live under constant persecution, and Angelise herself is one of many who want the Norma exterminated. But as Angelise's sixteenth birthday commences, it is discovered in a shocking revelation that she is actually a Norma. Chaos ensues, the public is outraged, and the once adored princess is exiled to Arzenal: a remote military base where Normas are forced into conscription. Now, the former royal must adapt to a harsh and vastly different lifestyle; piloting mechanical robots known as Paramail to fend off large, devastating beasts referred to as DRAGONs. However, a sinister truth about these savage creatures threatens to change everything.

Yui Komori, still held captive by the Sakamaki brothers—pureblood vampires after her blood—experiences yet more bizarre twists to her life following her stay at their household. Though haunted by enigmatic dreams, Yui soon deciphers their meaning when caught in a car crash, which subsequently leads to meeting four new vampires: the Mukami brothers, Ruki, Azusa, Kou, and Yuuma, who themselves capture the bewildered girl. Yui later awakens in the Mukami mansion, where the brothers reveal their plans for her: she is their Eve, and her blood will find the Adam among them; together, they will have the power to rule the world. However, with the Sakamaki brothers hot on their heels, things might not go quite as smoothly as they had imagined.