Sakutaro Komatsu (7, 47) was a Kuroko who had previously served Takeru's father, much like Ryunosuke serves Takeru. After the previous head of the Shiba House died, Sakutaro lost his will to continue as a servant of the Shiba House and took to the life of a fisherman. However, meeting Ryunosuke opens Sakutaro's eyes to the reason why he had served the Shiba House as he helps Ryunosuke in obtaining the Kajiki Origami. He later secretly resumes his duty as a kuroko; he helps Ryunosuke through his own crisis of confidence when Takeru is revealed to not be the real Head of the Shiba Clan.