Usually when you're reading one of these types of stories, it has a long opening period wherein characters are introduced One by One. This gives you a chance to get to know the various characters as Individuals before seeing how they fit into the Group Dynamic, allowing them to properly establish themselves in your memory. It also lets the Author engage in a bit of healthy World Building and laying down of various plot elements.
This Manga doesn't do that. Each Character just gets pretty much one Panel to explain their gimmick and then it's off. They aren't even spaced far apart in the first chapter. It honestly reads like this is missing a good Volume or Two of Introduction, and Chapter 1 is actually the first chapter of Volume 3 which has the small Refresher Introductions you tend to see at the beginning of a Volume.
The end result is that I read all three chapters and wouldn't be able to name or describe any specific character. I can tell you what Archetypes were present, or more accurately, which check-boxes on the Bishounen Hearthrob List were checked, because ultimately that seems like all the Story is interested in, and doesn't even have the originality to try applying some of those checkboxes to people who even look slightly unique.
Maaaan, when's Shinobi Quartet going to start updating again?