Copyright: the neon children
The Neon Children is a novel written by elix set in contemporary Japan. It stars Minoru Takahashi, his brother Kazuo, and his best friend Yuuki Sugitani. Minoru is your average fifth-grader, and he hasn't really hit puberty yet, both in the physical sense and in the sense of looking at girls (or boys) as sexual beings. All that's about to change, and that's just the beginning.
Elix and Arkaid have made a collaborative comic set in the same universe but with a separate storyline from the novel. This, and individual character illustrations and character sheets, are what land on e621.