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Filed by CPB Inc.
Pursuant to Rule 425 of the Securities Act
of 1933, as amended, and deemed filed
pursuant to Rule 14d-2 and Rule 14a-12
under the Securities Exchange Act of
1934, as amended
Subject Company: CB Bancshares, Inc.
Commission File No. 0-12396

        The following is a letter distributed to employees of CPB Inc. on April 16, 2003.

April 16, 2003

To Our Valued Employees:

        I am very pleased to announce exciting news of Central Pacific Bank's plan to merge with City Bank, a bank that shares our common roots, values and focus on customers. We strongly believe that the combination would create a stronger, locally based and managed bank that will benefit Hawaii. This combination is about growth for the future—growth that would be good for the local community, our customers, our shareholders and for you, our employees.

        As you probably know, many people have felt for some time that it would be logical to combine our two banks. We have invited City Bank's management to meet with us several times to discuss a potential combination. Today, we are making a public announcement of our proposal and hope that City Bank's management and board will enter into meaningful discussions with us. We believe this combination would enhance our ability to serve Hawaii's consumers and businesses.

        Combining our two banks would create a stronger, locally based and managed bank to fuel local economic growth and meet unique local needs. It would provide a local alternative to mainland-managed and foreign-owned banks. And it would be good for customers of both banks who could benefit from our fiercely loyal service, added convenience through an expanded branch and ATM network, and increased lending limits.

        As an employee, you have an important role in this process because—although we would be bigger—we would never lose sight of delivering high-touch, personalized service. Your commitment to deliver better service, better products, and a better banking experience for our customers has made us what we are today, and it would help the combined company continue to grow as the best bank for Hawaii.

        We are excited about the long-term opportunities this combination holds, and with your support we can create greater value for the local community, our customers and our shareholders.

        Tonight, we are holding a bank-wide employee meeting at 6:00 p.m., Hilton Hawaiian Village Coral Ballroom, to go over the specifics of this offer. We hope you will make every effort to attend this very important meeting.

Mahalo,

Clint

FORWARD LOOKING INFORMATION

This document contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Such statements include, but are not limited to, (i) statements about the benefits of a merger between CPB Inc. ("CPB") and CB Bancshares, Inc. ("CBBI"), including future financial and operating results, costs savings and accretion to reported and cash earnings that may be realized from such merger; (ii) statements with respect to CPB's plans, objectives, expectations and intentions and other statements that are not historical facts; and (iii) other statements identified by words such as "believes", "expects", "anticipates", "estimates", "intends", "plans", "targets", "projects" and other similar expressions. These statements are based upon the current beliefs and expectations of CPB's management and are subject to significant risks and uncertainties. Actual results may differ from those set forth in the forward-looking statements.

The following factors, among others, could cause actual results to differ materially from the anticipated results or other expectations expressed in the forward-looking statements: (1) the business of CPB and CBBI may not be integrated successfully or such integration may be more difficult, time-consuming or costly than expected; (2) expected revenue synergies and cost savings from the merger may not be fully realized or realized within the expected time frame; (3) revenues following the merger may be lower than expected; (4) deposit attrition, operating costs, customer loss and business disruption, including, without limitation, difficulties in maintaining relationships with employees, customers, clients or suppliers, may be greater than expected following the merger; (5) the regulatory approvals required for the merger may not be obtained on the proposed terms; (6) the failure of CPB's and CBBI's shareholders to approve the merger; (7) competitive pressures among depository and other financial institutions may increase significantly and may have an effect on pricing, spending, third-party relationships and revenues; (8) the strength of the United States economy in general and the strength of the Hawaiian economy may be different than expected, resulting in, among other things, a deterioration in credit quality or a reduced demand for credit, including the resultant effect on the combined company's loan portfolio and allowance for loan losses; (9) changes in the U.S. legal and regulatory framework; and (10) adverse conditions in the stock market, the public debt market and other capital markets (including changes in interest rate conditions) and the impact of such conditions on the combined company's activities.

Additional factors that could cause CPB results to differ materially from those described in the forward-looking statements can be found in CPB's reports (such as Annual Reports on Form 10-K, Quarterly Reports on Form 10-Q and Current Reports on Form 8-K) filed with the Securities and Exchange Commission and available at the SEC's Internet site (http://www.sec.gov). All subsequent written and oral forward-looking statements concerning the proposed transaction or other matters attributable to CPB or any person acting on its behalf are expressly qualified in their entirety by the cautionary statements above. CPB does not undertake any obligation to update any forward-looking statement to reflect circumstances or events that occur after the date the forward-looking statement is made.

With respect to financial projections for CBBI contained in this document, neither CBBI nor any analyst has published any information for 2003, 2004 or 2005. In addition, CPB has not been given the opportunity to do any due diligence on CBBI other than reviewing its publicly available information. Therefore, management of CPB has created its own financial model for CBBI based on CBBI's historical performance and CPB's assumptions regarding the reasonable future performance of CBBI on a stand-alone basis. These assumptions may or may not prove to be correct. The assumptions are inherently subject to significant uncertainties and contingencies, many of which are beyond the control of CBBI. There is no assurance that these projections will be realized and actual results are likely to differ significantly from such projections.

Subject to future developments, CPB intends to file with the SEC a registration statement to register the CPB shares to be issued in the proposed transaction, including related tender/exchange offer materials, and one or more proxy statements for solicitation of proxies from CPB shareholders, and may file one or more proxy statements for solicitation of proxies from CBBI shareholders, in connection with special meetings of such shareholders at a date or dates subsequent hereto. Investors and security holders are urged to read the registration statement, related tender/exchange offer materials, and proxy statements (when available) and

any other relevant documents filed with the SEC, as well as any amendments or supplements to those documents, because they will contain important information. Investors and security holders may obtain a free copy of the registration statement, related tender/exchange offer materials, and proxy statements (when available) and other relevant documents at the SEC's Internet web site at www.sec.gov. The registration statement, related tender/exchange offer materials, and proxy statements (when available) and such other documents may also be obtained free of charge from CPB by directing such request to: CPB Inc., 220 South King Street, Honolulu, Hawaii 96813, Attention David Morimoto, (808)544-0627.

CPB, its directors and executive officers and certain other persons may be deemed to be "participants" if CPB solicits proxies from CBBI and CPB shareholders. A detailed list of the names, affiliations and interests of the participants in any such solicitation will be contained in CPB's preliminary proxy statement on Schedule 14A, when filed. Information about the directors and executive officers of CPB and their ownership of and interests in CPB stock is set forth in the proxy statement for CPB's 2003 Annual Meeting of Shareholders.

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FORWARD LOOKING INFORMATION