Daihatsu is Japans oldest car maker. They always specialized in very thoughtfully designed small vehicles, but they did have a few larger offerings, some with 16V etc. They were especially good at pioneering and designing small, reliable and economical two and three cylinder engines.
Toyota had nothing comparable, and began buying Daihatsu shares. That process took may years, and since then, Daihatsu is totally Toyota owned. If you look at their smaller three and four cylinder designs, all that appears to be missing is the Daihatsu label. You may want to look them up in Wikipedia.