Mitchell Corp. — possibly best known as the creator of Pang, Polarium and Puzz Loop/Magnetica (which has been cloned as Zuma in the past) — is set to launch a new puzzle title on the Japanese 3DS eShop tomorrow (8th August).
Called Nagerupu Matrix — which roughly translates as Action Puzzle Matrix — the game appears to be a version of Puzz Loop which features real people instead of balls. The fact that the copyright says 1998 as well as 2012 lends even more weight to this theory (Puzz Loop was released in '98).
EDIT: Nintendo Life reader TsuchinokoX has a more accurate translation: "The Japanese says "Gyouretsu Nagerupu", which translated to "Throwing Parade Loop", the verb 投げる Nageru and the word loop being joined to form the second part, Nagerupu. The parade part refers to the procession of people that are formed when throwing the people and matching their colors."
As you can probably see from the video posted on the official site, it's all a bit strange. More content unlocks on the site tomorrow.
Thanks to Matt Sephton (AKA Gingerbeardman) for the tip!