Following the passing of his strict grandfather and ninja mentor Saizou, Kabamaru is entrusted to the care of a kind elderly lady named Ran Akoko. Believing in a letter supposedly written by his late grandfather, Kabamaru embarks on a journey to Tokyo with Lady Akoko. In the bustling city, he indulges in various delicious dishes like yakisoba and ramen, while also experiencing the peculiarities of attending a unique regular school with its own set of eccentricities.