[en] This report corresponds to Chapters I and II of Japanese contribution report to IAEA INTOR Workshop, Phase Two A, Part 2. The major objectives of the INTOR workshop, Phase Two A, Part 2 are to study critical technical issues, and to assess scientific and technical data bases, and to finally upgrade the INTOR design concept. To study critical technical issues that affect the feasibility or practicability of the INTOR design concept, the following five groups are organized; (A) Impurity control, (B) RF heating and current drive, (C) Transient electromagnetics, (D) Maintainability, (E) Technical benefit. In addition to those groups, the three disciplinary groups are organized to assess the worldiode scientific and technical data bases that exist now and that will exist 4-5 years to support the detailed design and construction of an INTOR-like machine, and to identify additional R D that is required; (F) Physics, (G) Engineering, (H) Nuclear. (author)