Itsuki is a young man of average height and build. He has short black hair and wears glasses.
Itsuki is very close with his sisters, even though Yuzuki Eba isn't related to him by blood where this nice attitude towards Yuzuki sometimes bothers Rin Eba because she thinks she acts nice to get attention.
Itsuki first appears knocking at the door of Aoi Kirishima's room where Haruto Kirishima and Yuzuki Eba were currently staying in. Looking for Yuzuki, Itsuki stated that his younger sister might be there, prompting Haruto to open the door to see him.
- The name Itsuki means "tree" (樹).
- Itsuki's surname Eba means "branch" (枝) (e) and "leaf" (葉) (ha/ba).