Shimon Shimon was Seine's third foster father and the one person who showed her kindness when she was young. He was known as a magician in his time and was also known to be 1700 years old (about 300 years ago in present time of the story). He bore the "Aion" mark, just like Seine does at the present time, but he had it across the right shoulder and was able to use Aion's power for his own, unknown, reasons. Seine is bent on revenge after the mermaid ate Shimon, but after Ariel said that they would "return" Shimon to Seine she just spit onto Seine's forehead, causing her to go into a coma-like sleep. Minagi Tatsuya's first cousin, once-removed, an elementary school aged girl. Her parents were the second and third ones shown in the story to be infected by a "mushi". Tsukasa Tsugawa family lawyer, responsible for managing Tatsuya's money until he gets old enough. Tatsuya calls him his "brother", which he explains as foster-brother since Tsukasa was in the house so much in earlier years. When he was first seen, he had been knocked unconscious by the Akuma twins and took a long time to regain consciousness. Creatures of Sea "Mushis" "Mushi" is the name of any kind of mind controlling bug. They infect humans by touch or bite. An infected human has a normal life until they see Seine's face, then they develop an irrepressible rage toward her and a desire to kill her. Seine usually refrains from destroying the mushi before the infected human kills her once, otherwise the desire to kill her remains even after the mushi is removed. Mermaids They are Seine's prey. They are 7 in all. As of the start of the story, Seine believes she has killed one of them. Up to chapter 32, five of them have been introduced and named. Sheila The youngest of the mermaids; she is despised by all her older sisters except for Ariel. Seine thought she had killed her some 300 years before, but Ariel restored her body almost entirely, leaving her badly scarred about the neck and unable to talk, but with the ability to change herself to have legs and walk about on land. She was introduced as a new transfer student; and Tatsuya is given the assignment of teaching her sign language. Her true goal is infect a lot of people