Crystals composed of the regular arrangement of atoms or molecules, exhibit unique functionalities derived from their structures. They serve as base materials supporting modern society in various applications. Producing these functional crystals requires advanced crystal growth techniques grounded in disciplines such as crystal science, crystallography, thermodynamics, and materials science, and the development of growth technologies is being performed worldwide. In our research group, we focus on functional crystals, conducting development based on unique, innovative manufacturing processes that span everything from nanoscale microstructural control to the growth of bulk single crystals.