Semileptonic B decays from Belle and Belle II

This report summarizes recent measurements of the CKM matrix elements |V₂₁|, |Vₔ₁|, and lepton-flavor universality tests in semileptonic B decays from the Belle and Belle~II experiments. The decay branching factions R (D^*) and R (X) are measured with the Belle~II early dataset and the results are found to be consistent with the Standard Model predictions. From a simultaneous measurement of untagged B⁰ ^- ^+ and B^+ ⁰ ^+, the |Vₔ₁| value is determined incorporating external theoretical constraints on the decay form factors. The first measurement of the full angular coefficients for B D^* decays at Belle provides comprehensive information for determining the decay form factors and |V₂₁|. This presentation also includes measurements of the ratios |Vₔ₁|^excl/|Vₔ₁|^incl and |Vₔ₁|^incl/|V₂₁|^incl.