Character development is key. Let Kano and Kido grow throughout the story. Maybe Kano starts off being a bit of a trickster but through his experiences with Kido, he becomes more responsible. Also, use vivid descriptions. Instead of just saying 'they walked', say 'they strolled along the cobblestone path, the sound of their footsteps echoing in the quiet alley'. This will make the story more immersive.
First, understand the characters well. Know their personalities, strengths, and weaknesses. For example, Kido is often seen as a strong leader, so make sure to incorporate that in the story. Then, come up with an engaging plot. It could be something simple like them spending a day together and learning new things about each other.