Kiku has long dark blue hair that she keeps in a braid over her left shoulder, and short bangs parted to the right side of her face. She has olive colored eyes.
She wears a school uniform with long sleeves, a navy blue collar and a knee length skirt, with a red scarf. She has a pair of black shoes and white socks.
Kiku is very kind and encouraging. She has a playful side as she teases Takeru about his fear of ghosts.
She is also very brave as seen when Ryujiro and his gang cornered her and she demanded they return her phone.
Kiku lives in a town in the country, where she spent time with Takeru. One day, she found him sleeping at the lighthouse. After waking him up, she warned him that he was going to be expelled if he kept skipping classes. Takeru admitted he didn't care, but Kiku reminded him that his grandfather would be worried. On the way home, the two found Ryujiro Mizunuma, his brother, and their gang bulling another student. Takeru gave them a warning glare and they left, which he did as well. Kiku apologized for Takeru's rudeness to the boy, saying he was actually very friendly. She noticed Takeru acting strange and he asked her if she heard a voice. She replied she didn't, then laughed saying it was too bright out for ghosts to appear.
The next day, at the lighthouse, Kiku looked up Playmaker and Link VRAINS on her tablet and shared it with Takeru. After showing him the article, she got a call from her friend Hana. When Takeru threw the tablet, she yelled at him before he told her it spoke. She thought that he had just turned the volume on.
Later that night, Ryujiro and his gang cornered her to lure Takeru for a duel. If he won, Takeru would be their minion. Kiku tried to talk Takeru out of it, but he accepted. Takeru then told her to go home, while she was hesitant to leave him, she followed his instructions.
Some time later, Kiku found Takeru at the lighthouse again, reading about the Tower of Hanoi incident. Again, she asked him to come back to school. He told her he would go, thinking he meant school she said it was four days until summer vacation. However, he meant he was leaving the city. When she asked why, he explained he was not himself, which just confused her more. While Kiku did not understand, she wished Takeru luck, saying he looked full of life, and and agreed to look after his grandparents.
Takeru is a close friend of Kiku's. Despite the boy's personality, she knows he's good at heart. She supports him and tries to convince him to return to school. When Takeru said he was leaving the city and asked her to look after his grandparents, Kiku did not ask for a reason and trusts his decision.