He is Asuka's personal secretary and also Jun's driver. Although he works for Asuka, he is more morally concerned with Jun's status not only as a human but also her demon side and he tries to help her as much as he can, often worrying for her well being, and showing immense displeasure at the way Jun is treated as a mere hunting dog with no regards to her own feelings or health. As the storyline progresses, he ends up getting caught in a conspiracy that may end up getting him killed and a shocking truth is revealed as he learns more of Lan Asuka's past and the future that she will unleash.
Maaya is a first year student at Tokiwadai Middle School, and is Kuroko's classmate. She is a member of the Swimming Club, same as Kinuho.
Daikichi's cousin on his mother's side and Reina's mother.
Manaka is Masaki's elementary-school-aged younger sister. She's a devious girl who first started having him dress up as a cute girll to impress Sumika and then sent pictures of him to a modeling agency that ended up hiring him. Despite her awareness of Sumika's feelings for Ushio, she fails to understand why Sumika rejected him and is angry with her for doing so, even going as far as to blackmail her to go on a date with Masaki. She doesn't take into much consideration Sumika's feelings or well-being nor her brother's embarassment, and her intentions motivating some of her schemes involving him are questionable...
Ayaka's older sister who fought and died as Saber's Master during the previous Holy Grail War. Highly regarded as a genius magus, her father had great expectations for her to win the War and to bring her family ever closer to the Root. Her level of talent would cause Ayaka (who had little talent for magecraft) to develop a superiority complex towards her. Over the course of the War Manaka would become attached to her Servant to the point of obsession, discussing the War and the Grail itself as they fought together. It would be later revealed that she had no intention of using the Grail's wish-granting power to reach the Root as her father desired. Having been born with a connection to the Root itself, Manaka would find her father's goal of reaching the Root "boring" and would instead offer human sacrifices to the Grail in an effort to raise the "Beast" (the Beast from the Book of Revelations), fulfilling the original purpose of Heaven's Feel (The Holy Grail War) to begin with. Realizing her true intentions and dark methods however, her Servant would stab her from behind at the end of the War, barely saving Ayaka from being sacrificed as their father already had and watching Manaka die with a smile on her face, unable to understand his betrayal. After her death he would throw her body into the Grail, ending the War with no victor. As the next Holy Grail War began Manaka would be resurrected by the power of the Grail as the 1st Master of the War, Seraphim, becoming the final antagonist of the story with the Beast itself as her Servant. Despite her death by his very hand she would become even more obsessed with Saber, calling him her "Prince" and expecting him to come back to her. (Source: TYPE-MOON wikia)