- “I know you said you weren't planning on being friendly, but I like you”
- — Denki to Hitoshi.
Denki and Hitoshi do not interact until the Joint Training Battles, in which they team up. Despite his distant and cold attitude, Denki tries to strengthen ties with him, even defends him when Katsuki describes him like a dead weight for the exercise due to his lack of experience.
After the initial clash with the 1-B team, Hitoshi is well aware that his inexperience in battle and apologizes for his slowness in capturing Jurota Shishida, but Denki points out that what he was able to stop Jurota, avoiding the total defeat of 1-A team, and tells Hitoshi that he likes him and he's rooting for him to become a great hero some day. Denki compliments Hitoshi a lot during this time.
At one point, Denki casually states, “You have the face of a popular guy. I’ll bet you’re popular with the ladies, yeah? Trust me, I can tell..” This line easily, if not directly implies that Denki finds Hitoshi to be rather attractive.
Their friendship is often compared to SirMight, EraserMic, MiriTama, and KiriBaku, thanks to the introverted dark-haired (with the exception of Katsuki’s blonde) boy/man x loud blond extrovert trope. Kaminari commenting on his looks has caused many fans to think he is bisexual.
There is a considerable amount of content for KamiShin, especially on Tumblr and AO3. There is also a lot of memes and fanfictions that mention Present Mic, Kaminari, Kirishima, Mirio, and Deku becoming friends with Eraserhead, Shinso, Bakugo, Tamaki, and Todoroki respectively, due to the parallels. Prior to meeting the first five listed characters, the latter five had no close friends but warmed up after meeting them.
Many see their relationship in a sweet and innocent light. Usually with Kaminari being one of the rare people who do not fear or shun Hitoshi for his powerful quirk, and interacts with him despite of the dangers of being brainwashed. Shinso's cold exterior slowly crumbles the more he hangs around Kaminari. In fan works like these, Hitoshi has already transferred to the hero course and is in Class 1-A, where he is quickly befriended by Kaminari and his friends.
There are also AUs where Shinso gave up on his dream of becoming a hero due to his quirk being so frowned upon and ends up becoming a member of the League of Villains. But he falls in love with someone who accepted him for who he is (Kaminari) and betrays the League for the heroes.
On AO3, KamiShin is the most written ship for both Hitoshi and Denki.