Kei's grandfather, Kaname Takishima, is the head of the Takishima group and is a powerful man in a business world. He often tries to tear Hikari and Kei's relationship apart. He has a very bad relationship with his daughter, Midori, who is also Kei's mother.
He is rarely seen by others, including his own family members. He makes his first appearance in chapter 25, when he makes a phone call to Kei's father. When Hikari speaks with him over the phone, he plants the idea in her head that Kei is burdened by her very presence. She meets him face to face in Chapter 59, when President Takishima tries to convince Hikari to transfer schools. He disapproves of Kei's relationship with Hikari and makes many attempts to separate them, such as sending Aoi, arranging marriage meetings for Hikari in London, and arranging a marriage between Kei and a girl named Alisa. The President expresses a strong dislike of Hikari and the mere sight of her sickens him. It is eventually revealed that he feels that he and Hikari share similarities that will make the people they love suffer; as a result, he fears that if Kei remains with Hikari, he will endure the same fate as his grandmother did.
In the manga, he wears a bunny suit to his daughter's party, which turned out disastrous for both of them. Midori seems to hate him, for she blames Kaname for the death of her mother, Izumi Takishima. They later reconcile but still have a tense relationship.
Kei seems to have a dislike to his grandfather, who is constantly trying to split Hikari and him apart. He sends Kei to London and did many things to try severing his ties with Hikari. However, Kei helped Hikari reconcile Kaname and Midori.
He is utterly disgusted and disappointed with her, even though she is girl with no stat around with Kei. Even with desperate hopes of tearing them apart, Hikari is always kind to him, helping him with s, hanging many things such as the case with Midori.
Izumi Takishima is the deceased wife of Kaname Takishima. Everytime Kaname knew he did something wrong to Izumi, he would always give Izumi her favorite types of flowers, which she called "happy flowers" because they would always make her happy everytime.