Kosuke, a chill, polite person who is your close childhood friend. Very kind to other classmates. One he achieved a "Character Award" from the school for being kindhearted to everyone. Sometimes other classmates would joke at him for being too kind. But sometimes they'd also joke at him about his "obsession" in biology books. Therefore, he's nicknamed as "biology nerd". Despite all of that, he doesn't see it as an insult. Instead, he see it as a joke or a compliment.