The inclusive reconstruction of Charmed Mesons on B-factory

We present the study of the inclusive branching ratios of the double charmed decays with strangeness B → $ \overline D ^{^{(*)} } D_{s(J)}^{(*)} $ The study based on the missing mass distributions in inclusive transitions B → $ \overline D ^{^{(*)} } X $, and thus in a way free from the assumptions about resonance decays $ D_{s(J)}^{(*)} $. There are also presented the perspective of such studies on the next generation Belle II experiment.