Himari

Himari (ひまり, Himari) is a young girl introduced in A Sunset With Izaya Orihara. After an event orchestrated by Izaya Orihara, Himari's father murdered Haruto's father. With her mother in the hospital, she is taken under Izaya's wing along with Haruto. 

Personality
She is darker and more cynical than Haruto but does not speak much. She is a smart girl who acts much more like an adult than a child.

Background
Himari’s father was close friends and business partners with Haruto’s father. When their business succeeded Haruto’s father took all of the credit and became the director of the company. Himari’s father perceived this as a betrayal and hired Izaya to find an opportunity for him to kill the director and take all his money but omitted that director had taken the reins of the company so he could take the full blame for a huge problem in the company and protect Himari’s father, who he would then leave the company to. Himari’s father, only learned this after killing Haruto’s father and killed himself upon realizing the truth.

Following this, Haruto's mother fell out of sorts with Himari's mother and stabbed her before attempting to kill herself and both the children. Haruto's mother was sent to a mental institute while Himari's mother was hospitalized for her injuries. Due to this, Haruto and Himari were left temporarily parentless. At an unspecified time Izaya appears to them and takes them under his care as their guardian.

A Sunset with Izaya Orihara
Himari and Haruto are brought to Bunokura with Izaya and help him with tasks he assigns them. They first approach Sasazaki and bring him to Izaya at the Bunokura Grand Palace hotel to discuss negotiations. Sometime later the two children accompany Izaya to the park in town to talk with Azami Niiyama, a maid at the Adamura residence. After Izaya finishes talking with her, Himari approaches Azami before they leave and warns her to try and not get involved with him for her own good.

Two days later, they tag along with Sozoro to help and retrieve Douma Kiyojima for Izaya. The two bolt the door so Douma and his men could not escape, and Himari used a jamming device to prevent the group from calling for backup. After Izaya finishes talking to Douma and brings in Nana and Kazuhisa, he tasks Himari to give a cell phone to Azami so she could make contact with him.

The day of the political gathering at the Grand Palace hotel, Izaya meets with Sasazaki in the underground parking garage. When Usubara and the Oukarengou members arrive, Haruto and Himari move Izaya into a hiding space before grabbing a fire extinguisher and using it on the men. They escape through the elevator amidst the chaos and head with Izaya to the event.

Izaya Orihara
Himari loathes Izaya, aware of his involvement with her father and the destruction of her and Haruto's families. Her detestation towards him is significant enough where she has even stated she hates Isozaka and Nec for working with him, even though she admits she would like them normally otherwise.

She considered Izaya to be someone out of her league and someone no one could stop, until she heard from Mikage and Kine that Izaya had lost to someone in the past. This gives her the motivation to improve herself and surpass Izaya. While she despises him, she does acknowledge and respect his abilities enough to try and emulate him to an extent, believing if she can become like him or better than him she can return Haruto to his original state of being and not cling to him.