Appearances

Chapter 1: Jeile casting the spell on Aram.
Chapter 2: Jeile sending guards to look for Aram.
Chapter 3: (the short first true appearance) Jeile coming to Airi's world through the mirror to look for Aram - at the end.
Chapter 4: Confrontation with Aram/Airi at the beginning. At the end he kidnaps Airi, bringing her back with him to Astelle.
Chapter 5: Jeile attempts to win over Airi, while facing off with Aram too. Eventually Jeile's side of the story is revealed, and he lifts the spell off Aram (to no effect).

Chapter 8: At a ceremony open to the public. Airi also appears here and Jeile tries to get to her, but is held back by Lei.
Chapter 9: Jeile attempts to save Airi but is stopped by the Queen, who threatens him.
Chapter 10: Jeile appears in Airi's world as a teacher, along with many other members of Astelle to Airi's surprise.
Chapter 11: Jeile leads Airi's class in their school trip to the seaside.

Chapter 12: Jeile continues playing his teacher role. At the end though, he exercises some authority by taking Razu back, who was attacking Airi and Aram.
Chapter 14: Jeile tries to comfort/cheer up Airi, who is devasted by Aram's loss of memory of her. He even offers to help her despite her outright rejection of him (he attempted to change her mind about their relationship as lovers).
Chapter 15: Jeile tells Aram off (gently) to not be rude to Airi, upset by the fact that she was asked to be Aram's 2nd wife. He also releases her from the prison (Razalude's doing).
Chapter 16: Jeile tries to help Airi (while making her wear a maid uniform, since she's under the pretense of serving him). However he is pulled away by officials due to work issues, but returns briefly later (since he ran away from them). He also reveals to her the cause behind Aram's partial memory loss.
Extra: Jeile's first meeting with Aram when they were young, as well as with Lei.

Chapter 17: Jeile goes to Airi's rescue who is stuck with Razalude alone, along with Aram. At the end, Jeile also gives her up for her happiness seeing Aram propose to Airi and her accepting.
Chapter 18: Jeile tries to lighten up magic class (Airi's and Aram's of course) by taking over the teacher. The brothers share some time together too (at Airi's expense).
Chapter 19: Once more, at a ceremony. Nei is also introduced here as Jeile's future wife. He and Nei escape the 2nd ceremony though by transforming into children.
Chapter 20: Jeile oversees Airi's return to her world. But he and Aram intrude too, allowing the three of them to share a serious moment.
Chapter 21: Jeile's past with Maruru is revealed, and Nei is brought closer to both of them at the end too.
Final Chapter: Jeile oversees Aram and Airi's wedding, casting yet another spell on Aram. His two children with Nei are shown too.