World's Finest is a story written by Takiguchi Aiko and illustrated by sakkiarte. It ran in Issue 16 at http://s2b2.livejournal.com/93799.html, and is mirrored at http://www.shousetsubangbang.com/mirror/worlds-finest/.
From pinboard.in: "Teenage superheroes go undercover at a boarding school, and have to solve crime AND deal with their romantic woes. Lovely homage, and simply a fun and delicious read. Also check out the space opera style sequel."
From pinboard.in: "Heavily based on DC universe, Elias is this universe's Robin, a superhero by the name of Stalker, and currently undercover at Sinclair Wellington; Zac's an Ultra, a metahuman or really, a deposed prince from another planet, and Elias' ex-boyfriend. He transfers to Sinclair to help Elias uncover the mysterious murders happening there, but more to uncover why Elias dumped him and left the Young Commandos, a team of young superheros."
From pinboard.in: "Superheroes (with powers and without) kind of familiar. Case study type fic where Elias is undercover at a boarding school with mysterious deaths, not to mention the fact that his annoying ex Zac (fellow superhero-with powers) shows up to "help" (read:annoy)."
World's Finest is followed by the aforementioned space opera style sequel, The Brave and the Bold.