Press release
May 15, 2006

Sosei Announces Company Name Change of two Affiliates

Tokyo, Japan/London, UK – 15 May 2006: Sosei Co. Ltd. (TSE Mothers Index: 4565) announced today that its two affiliate companies, Arakis Ltd. in the UK and Kosei, Inc. in the US, change their company names to unify corporate identification within the Sosei Group.

Detail of the company name change


Current company name             Arakis Limited

New company name                 Sosei R&D Ltd.

Business                                   Biopharmaceutical Research and Development

Address                                     Chesterford Research Park Little

                                                  Chesterford, Saffron Walden

                                                  Essex CB10 1XL, United Kingdom

Representative                          Robin BANNISTER, Managing Director

Effective                                    1 June, 2006


Current company name              Kosei, Inc.

New company name                   Sosei Inc.

Business                                     US base

Address                                      630 Fifth Avenue, Suite 2005

                                                   New York, NY 10111, USA

Representative                           John DAFFURN, President and CEO

Effective                                     28 April, 2006