Rainbow Girl

(from ebookjapan):
In order to take over the company, the president of Tokyo Electric Company, an executive of the company, Kuroi, tricks the president into setting up the president's wife as a spy and locking her up. His young beloved daughter Ako, who was abandoned at the time, is picked up by a woman who, by chance, entrusts her with a treasure map. Mrs. Kuroi's siblings come to Tokyo from Osaka to look for the missing Mrs. Kuroi and Ako, but they are interrupted by Kuroi's men and an organization that wants Ako's map, and the case becomes complicated. ......