Crayon Shin-chan: I'm Shin-chan's Uncle

Zehei, a typical aimless young man of the new era, unexpectedly becomes Shin-chan's uncle. Looking at the familiar potato-like boy before him, what interesting things will happen between the protagonist and him? (This book includes theatrical versions and urban legends, but is primarily slice-of-life. There is a female lead (Nanako) at the end, but she has a small role.)