Heartful Memories ~Little Witch Parfait 2~

The protagonist, Perky, has only his name to remember, but nothing else in his memory to confirm his true identity. He is found unconscious by Parfait Sucreal near the Crabell Waterfall outside Florelmos. When Parfait allows him to recover in her house and informs him about Florelmos, as well as herself, she takes Perky to the wise witch to see if she knew anything about Perky.

Unfortunately, the wise witch says she is not able to claim his identity but that he owns 500000 gold in return for keeping her keeping his sword for him. Until he collects the money by 6 months, the wise witch tells Parfait to allow Perky to stay in the Black Cat Market.

[Edited from Wikipedia]