Sumio Haiba is the only son of Mina Haiba and his unnamed father. He is the protagonist of the ǝnígmǝ series

Spoiler

He was chosen by his old childhood friend, Kirio Imizuka, under the alias of ǝnígmǝ, to attend the fifth e-test. As of the end of the e-test, he has taken over possessing and taking on the identity of ǝnígmǝ from Kirio.