The main character of the manga. Jim is a boy magician with only half a heart. His best friend Luca betrayed him and cursed him when they were young, sending him to a purgatory of "nothingness" for 100 years, to which after that he is allowed 10 days of freedom to get back his heart. If he fails, he will return to the "nothingness" and wait for another hundred years. He is at odds in Magic and depends on his Physical Strength. Back in the days, he was known as the Dunce of the Magic Academy. It was in that time he first met Luca and became friends. It was later he was tricked in giving half his heart and in doing so leaving all those he loves as he can only come back every 100 years. The beginning of the volume shows episodes of every 100 years he has 10 days to find Luca. He is released near Luca as they share hearts and each one he is close but helps those he visits over getting his heart back. The curse is supposed to make him always to be alone.