Koichi Shindo

Koichi Shindo (also spelled Kouichi Shindou) is a supporting character in the Horimiya anime (the 2021 adaptation). He is Izumi Miyamura's best friend from their middle school days—the only one who truly reached out and befriended him when Miyamura was largely ignored or outcast by others.

In the anime, Koichi is portrayed as a cheerful, upbeat, and kind-hearted guy who's almost always smiling and full of positive energy. He's outgoing and was quite popular in middle school due to his friendly, approachable nature. Despite attending a different high school (Yasaka High) from the main cast, he remains close to Miyamura, often teasing him playfully (and getting teased back), showing how comfortable and brotherly their bond is—one of the few people who can easily rile Miyamura up or make him act openly annoyed in a lighthearted way.

Physically, he's depicted as tall and lean with distinctive spiky orange-ish hair (medium-length and flicked outward) and green eyes. He's in a relationship with Chika Ichijou (a girl from his school), and their dynamic adds some fun side moments when their paths cross with Miyamura's circle.

Overall, Koichi serves as a reminder of Miyamura's pre-high school life and brings a lot of warmth and humor through his genuine, non-judgmental support for his friend.