Izumi is a man who appears to be in his 20s or 30s, and is the leader of the organization known as Arcana, who are also searching for God's Inheritances.
Izumi is a fairly tall man, who wears professional clothing.
When he is first introduced, he has short, wavy black hair.
Later on, after using his powers "for the first time in a long time," according to Izumi himself, his hair grows longer and turns blonde. This change in his appearance isn't explained in-depth, other than it being related to the use of his powers.
Nothing is known about Izumi's history.