Souta Hori (堀 創太) is the son of Kyousuke Hori and Yuriko Hori and the younger brother of Kyouko Hori. Izumi Miyamura first encounters him when the boy is attacked by a dog; Miyamura brings him back home, meeting Hori in the process.
The cutest relationship with a sense of bonding, we have Izumi Miyamura and Souta Hori. Miyamura and Souta had a brother-friends relationship. Souta was very fond of him and he addresses him by the term “cool guy”.
Souta Hori was Hori-san ‘s brother from the anime, HoriMiya. HoriMiya is a Japanese anime following the story of a high school friend, later becomes a couple. In the anime, we have Miyamura and Souta both have a relationship where Souta gets a big brother as well as a friend.

Souta was elated to have him with her sister as well as at home. He often asks her sister to call him in the house so that he can play with him and secretly he was z that now his sister does not find herself all alone and simultaneously he helped her in house chores as well.
Miyamura also liked Souta very much and finds him cute as well. Miyamura also said that he is well-mannered and always thinks about her sister and worries about her. They often had many days when they both played together and ate cakes that were brought by Miyamura from his family’s bakery shop.
How they both met?

Miyamura and Souta met first when Miyamura helped him from falling as Souta got scared by a dog. Miyamura took him home and since then they became very good friends. Whenever Miyamura comes to Souta’s house, Souta always gets excited and gives him hugs.
Souta loved to sit in Miyamura’s lap and loved being there with him. As a kid, he never got any male elder in his company with whom he can play and enjoy himself. He was very interested in Miyamura and Hori's relationship as he wanted them to be together. Souta finds Miyamura a good-hearted person whom he can trust.
Though they both were not real brothers or not even related as their last names were different, they still had an overwhelming relationship. They spent enough time together and they had a relationship that no other real brothers have. Souta is a child, who can be very direct in many things and not feel embarrassed by talking about topics that her sister could not.
When Souta saw Miyamura and Hori wearing rings he expressed his happiness and joy, thinking they were both getting married. He was very excited to have Miyamura an official member of their family and be a part of them in every moment and situation.
He was well aware of the fact that Miyamura and Hori had feelings for each other before they even knew. Despite being a child he was a little mature in many ways; he even stayed at school late so that Hori and Miyamura could spend more time together.
Were they fond of each other?

From many scenes, we can also see that Souta trusts Miyamura a lot and he wanted him to always be there with them. As a child, he plays with Miyamura every time he comes home. He was like a brother who was proud to have a boy like Miyamura to be his sister’s lover. He felt happy when he discovered that his sister and Miyamura both secretly developed feelings for each other.
The anime shows their relationship where Souta finds himself an older brother and a friend like a family member. Even Souta’s parents were extremely glad to have Miyamura as their children’s friend. Miyamura was very well aware of Souta’s favorite books and cake.
When Miyamura got him a book, he was very happy and also showed it to his mother, being very excited and all. He was kind of flaunted to have Miyamura his older brother and was very fascinated by Miyamura’s cool look; his piercings, hair, and how he dresses up. They enjoyed each other's company a lot and admired each other as well.