Izumi is a shinigami who appears later in the story. He is somewhat cold-hearted and distant, particularly in the anime. Of all the characters in the series, Izumi is the only one whose personality and plot role are noticeably different in the manga and its anime adaptation.
In the anime, Izumi's background story is not mentioned and he is portrayed throughout as a cold-hearted character, often as the serie's main antagonist. He makes several attempts to steal Mitsuki's soul over the course of the series, and although he claims to love Meroko, he only seems to do things that cause her pain (as Takuto points out). It is also revealed later that he was the one who assigned Takuto and Meroko to Mitsuki in order to force Takuto to remember his past life as a human by taking the soul of the daughter of his former friend.