Principal subject of Seno Labo is the mathematical model analysis to make clear or present the point at issue for scientific discussion about biological/social phenomena, or to promote the advanced theoretical research. We focus what theoretical problem about target phenomenon is treated, how the problem is mathematically modeled, what mathematical analysis is applied for the model, and how the mathematical result is lead to the discussion in biological/social science. Especially important is the modeling of mathematical model as simple as possible, which is based on the principal purpose of research for target phenomenon, and our study necessarily focuses the rational consistency/adaptability of mathematical modeling to assumption/hypothesis about biological/social phenomenon. Seno Labo attacks a variety of theoretical problems about biological/social phenomena in wide range of spatial/temporal scale, analyzing basic models constructed with application of stochastic process, difference equations, differential equations etc. They are aimed to make clear the point at scientific issue and to provide some bases of mathematical modeling for advanced/applied researches about real phenomena.