Itsuki Sumeragi

Itsuki Sumeragi (イツキ・スメラギ Itsuki Sumeragi) is the doting brother to Erica Sumeragi, and the heir to the Sumeragi house.

Trivia

 * In an interview, the author revealed that Itsuki wasn't in the original draft, his character was only created when writing the chapter before his debut, as the author realized that the Sumeragi house would not have an heir once Erica is married into the Stokes house.