The main character is the prince of the Popolocrois kingdom, Pietro. The first game, "Popolocrois Monogatari", starts at the night of Pietro's 10th birthday, when he learns that his mother, who he thought was long dead, was found in a coma. Pietro sets out into a journey along with the apprentice forest witch, Narcia, to save his mother's soul from the underworld.
That is only the beginning of the Popolocrois story, there are two more games continuing the tales of Pietro and Co. The second game, "PopoRogue"(Popolocrois + Epilogue), featured Pietro as a 12 year old boy that went off to save his father from the dream world that he was forced into. The third, "Popolocrois Monogatari II", featured Pietro and Narcia as a 15 year old with different costumes, who went off the defeat the mysterious force that was going to destroy the world. "Popolocrois Monogatari II" was the most famous game of the series, due to the darkened story, new party members, and many other features.
The PSP release is a reproduction of "Popolocrois Monogatari" (included into Book 1) and "PopoloCrois Monogatari II"(Included into Book 3), but Book 2 is a brand-new scenario.