Daiki Niwa

This character is a significant figure in the story, serving as the grandfather to Daisuke and the father to Emiko. Forty years ago, he was involved in the Dark, and he approached the act of stealing with a pragmatic, job-like attitude, contrasting with Daisuke's approach. While perhaps less prominent in the anime adaptation, he features frequently in the manga and is often portrayed with a lighthearted and amusing personality.