He is a professor at the Research Institute for Mathematical Sciences (RIMS) at Kyoto University.
In a joint work with K. Fukaya, he constructed Floer cohomology of Hamiltonian diffeomorphisms on arbitrary closed symplectic manifolds as well as Gromov-Witten invariants.
In recent years, he has been collaborating with Fukaya, Oh and Ohta in Floer theory for Lagrangian submanifolds and its implications in symplectic geometry and homological mirror symmetry.
[5] In 2006 he was an Invited Speaker with talk Development in symplectic Floer theory at the International Congress of Mathematicians in Madrid.
In 2022, he serves as Director of the Research Institute for Mathematical Sciences of Kyoto University (KURIMS).