You start Professor Layton and the Century of the Seven Phantom Thieves by making an avatar. Then you gather information to catch criminals. If you’re victorious you’ll get a reward (probably an avatar item). Professor Layton and the Century of the Seven Phantom Thieves has a social mechanic where you can cooperate with other players to get an advantage when battling with thieves.
If you register for the game early you’ll get a Luke puppet, a rare avatar item, as a gift. While the business model hasn’t leaked online yet, it kind of sounds like this Layton game will use a paid per item system.