Understanding of diverse phenomena observed in various materials requires a precise theoretical analysis of interacting quantum systems, which is often difficult. Nevertheless, in recent years, there has been a significant progress in mathematical methods on interacting quantum systems, especially on the exactly solvable ones.
 Exactly solvable systems in one dimension used to be regarded as "toy models" for theorists. Recently, however, they are of increasing importance also for experimental studies, thanks to fabrication and synthesis of quasi one-dimensional systems and materials. The problems in physics have also been a source of new mathematical concepts.
 Professor Minoru Takahashi has made several lasting contribution to the field. This workshop is held on the occasion of his retirement from ISSP, University of Tokyo.
 At the workshop, diverse topics ranging from mathematics to experimental magnetism will be discussed, to stimulate further development of related fields.