Amakusa Ryu

Amakusa Ryu is a Q Class student and one of the main protagonists.

Ryu is the heir of the criminal organization Meiosei (Pluto). He is also the grandson of its founder, King Hades. Because of his grandfather's wishes, he was forced to join the detective academy, DDS, and be under the wing of his grandfather's arch-nemesis, Dan Morohiko. Ryu is a very intelligent guy who is also very quiet. He barely talks, unless Renjo Kyu asks him questions or when he explains a case's tricks. During the first part of the series, he usually avoids contact with the group and would prefer to solve the case on his own, but as the series progresses, his nonchalant and uncaring attitude towards the group changed. He began to really care a lot about Kyu and Minami Megumi, to the point of going as far as taking the knife meant for Kyu.

Ryu is King Hades' grandson. When he was 5, he was taken by his parents to an academy for the gifted children where he met Minami Megumi. Unfortunately, his memories were erased by King Hades, along with Megu's memory about Ryu.

In the anime and live-action, he was taken care of by Miss Yurie. Throughout the series, Ryu was never seen with his parents and no one knew who they were.

Ryu is very knowledgeable and has a brilliant mind since he was a child. In both the anime and manga, he is also shown as someone who knows self-defense. This was because according to him when he was young his grandfather prevented him from going outside to play with other kids. He was forced to stay inside their house to learn how to be the successor of Meiosei. As proof of being part of Meiosei, he has a tattoo on the back of his neck.

He is voiced by Kōichi Tōchika (anime) and in the real Tantei Gakuen Q drama, Ryu was played by Ryosuke Yamada, an actor and also a singer from Japan's famous boyband: Hey! Say! JUMP.