Minato visits a recitation at an anime event with his friend. He is captivated by the voice actors' performances and decides to enroll in Suidoubashi Animation Academy. There, he meets Chikako, who used to live in the room he is moving into and who left a message in a USB drive. Minato, who aims to be a voice actor but is unable to put himself into the role, and Chikako, who lives with a past trauma, encourage one another and try to improve themselves. With the help of seniors such as Ryouta and Kei watching over them, they try to mature. As they stumble and worry, what lies ahead for them both?

The skilled craftsman Kuroda created artificial humans called Hybrid Child—creatures who are neither machines nor dolls, but rather a reflection of the love shown to them. While they can feel human emotions and have their own consciousness, they are not real humans and require love to grow. Kotarou Izumi is the young heir to the noble Izumi family, so it is frowned upon when he brings an abandoned Hybrid Child he found in the garbage into their household. His family even attempts to throw away Hazuki—Kotarou's name for the Hybrid Child—multiple times when he is not paying attention. But through overcoming these obstacles, their love and the bond connecting them grow stronger. However, ten years pass before a horrifying realization dawns on them: a Hybrid Child might not have an endless life span. Hybrid Child is a collection of three short love stories, depicting the relationship between the artificial humans and their owners.

The story focuses on high school girl Nagisa Yukiai who lives in a seaside town. She has believed her grandmother's story that spirits dwell in words and they are called "kotodama" (word spirit). One day, she strays into a mini FM station that has not been used for years. As an impulse of the moment, she tries to talk like a DJ using the facility. But her voice accidentally broadcasted reaches someone she has never expected.

At last, the Sanzou Party has arrived in India. In this foreign land, where the anomaly's influence runs rampant, their battles only heighten in their violence. And also awaiting them is their tragic fate from 500 years ago— What will they find at the end of their long and treacherous journey?