The main theme for my research in mathematics is “spaces with symmetry”. I am particularly interested in the field in which algebra, geometry, and combinatorics (three different kinds of mathematics!) intersect all at once. For those area of mathematics, it is often happens that a single phenomenon has many ways to be viewed; it can have geometric interpretaions, representation theoretic interpretations, and combinatorial representaions. Through these experience, we can feel the richness of mathematics. In particular, it is exceptional when we can express abstract geometric/topological quantities in terms of concrete algebra and combinatorics. Recently,I am particularly interested in the geoemetry and topology of Hessenberg varieties.