De novo development of molecular catalyst (MC) for a targeted ideal reaction is challenging and requires deep understanding of chemistry. Irrespective of the how and why for the finding of high performance MC realizing high reactivity, turnover frequency, selectivity, and productivity, the mechanism should be pursued because it offers a great source of creativity. A detailed mechanistic study of Oguni asymmetric reaction catalyzed by DAIB-Zn complex (DAIB: 3-exo-dimethylaminoisoborneol) has established a new leading concept, that is “Donor-Acceptor Bifunctional Catalyst (DACat),” for the design of a MC. The concept has been categorized into four by two parameters: i) intramolecular (Intramol) or intermolecular (Intermol) and ii) metathesis (M)- or redox (R)-type reaction. The four concepts have realized a new type of MCs including asymmetric hydrogenation of ketones, allyloxy bond cleaving reaction, and asymmetric dehydrative allylation. This account overviews the results obtained in our group.