This is also the episode 5 of dramas His Cure His Wife; In Bound By Love Episode 5, that person turns out to be Luca's little brother, Matteo Vitiello. He greets Luca and briefly flirts with Aria in front of him, only to introduce Aria to his future bride. That's Aria's little sister, Gianna! So, does it mean Gianna is also forced to marry into the Vitiellos?
