<PAGE>

                                                                   EXHIBIT 10.38

FIRST AMENDMENT TO LEASE DATED SEPTEMBER 15, 2004 ("LEASE") BETWEEN MISSION OAKS
ASSOCIATES, LLC ("LESSOR") AND DECKERS OUTDOOR CORPORATION ("LESSEE") FOR 3001
MISSION OAKS BOULEVARD, UNIT B, CAMARILLO, CA 93012 ("INITIAL PREMISES").

      1.    For reference purposes this First Amendment shall be dated December
            1, 2004.

      2.    Lessor has agreed to extend the free rent period on the Initial
            Premises for an additional forty five (45) days in exchange for the
            term of the Lease to be extended for an additional forty five (45)
            days. As a result, the Base Rent payable by Lessee and term of the
            Lease on the Initial Premises shall be as follows:

<TABLE>
<S>                                 <C>
10/01/04-01/14/05                   $        0/month NNN
01/15/05-05/14/05                   $   29,000/month NNN
05/15/05-11/14/05                   $   42,000/month NNN
11/15/05-11/14/06                   $   46,000/month NNN
11/15/06-11/14/07                   $   50,000/month NNN
11/15/07-11/14/08                   $   54,000/month NNN
11/15/08-11/14/09                   $   58,000/month NNN
</TABLE>

      3.    Lessee has agreed to lease Unit C at 3001 Mission Oaks Boulevard,
            Camarillo, CA 93012 ("Expansion Premises") which is located adjacent
            to the Initial Premises as depicted in Exhibit A. The Expansion
            Premises is comprised of approximately 75,000 square feet. The term
            of the Lease for the Expansion Premises shall be from December 1,
            2004 through November 14, 2009. The Base Rent on the Expansion
            Premises shall be as follows:

<TABLE>
<S>                                 <C>
12/01/04-01/14/05                   $        0/month NNN
01/15/05-01/14/07                   $   29,250/month NNN
01/15/07-01/14/08                   $   33,750/month NNN
01/15/08-01/14/09                   $   36,750/month NNN
01/15/09-11/14/09                   $   40,500/month NNN
</TABLE>

      4.    Lessee is accepting the Expansion Premises in its as-is condition
            except that Lessor shall be responsible for installing new ballasts
            in all of the light fixtures located within the Expansion Premises.
            Lessor shall have the new ballasts installed within the Expansion
            Premises by December 31, 2004.

      5.    Effective December 1, 2004, the Premises shall be defined to include
            the Initial Premises and the Expansion Premises.

      6.    Lessee's share of common area expenses shall increase from 10,000 to
            17,500 as a result of the inclusion of the Expansion Premises.

                                       1
<PAGE>

      7.    Lessee shall have the right to seventy five (75) parking permits for
            the Expansion Premises pursuant to the terms of the Lease. These
            parking permits coupled with the one hundred (100) parking permits
            already provided for with the Initial Premises shall provide Lessee
            with a total of one hundred and seventy five (175) parking permits.

      8.    Article 53 contained within the Addendum to the Lease shall be
            revised as follows:

            Lessor shall construct, at Lessor's sole cost and expense, a
            division wall between Unit A and Unit B (see Exhibit B). The
            division wall on the Unit B side of the wall shall be constructed of
            5/8" drywall (non-taped) from the floor to the ceiling. The drywall
            shall be painted. Any leasehold improvements installed and
            constructed by Lessor must comply with applicable building code
            requirements. Lessor shall not be responsible for constructing a
            division wall between Unit B and Unit C.

            Lessor shall utilize commercially reasonable efforts to commence
            construction of the division wall between Unit A and Unit B by
            December 13, 2004 and to complete the installation of the metal
            studs that will support the division wall and the installation of
            the drywall (inclusive of painting) on the Unit B side of the
            division wall by December 31, 2004. To the extent that Lessor does
            not complete the installation of the aforementioned metal studs and
            Unit B side of the drywall (inclusive of painting) by January 14,
            2005, Lessee shall receive a day for day abatement of Base Rent on
            both the Initial Premises and the Expansion Premises. For example,
            if the installation of the metal studs and Unit B side of the
            drywall is completed on January 20, 2005, this is six (6) days
            beyond the January 14, 2005 deadline therefore Lessee shall not be
            obligated to commence with the payment of Base Rent on both the
            Initial Premises and Expansion Premises until January 21, 2005.

            Lessee acknowledges that Lessor has been informed that it needs to
            install an exit corridor within the Initial Premises as depicted in
            Exhibit B. This corridor shall be constructed at Lessor's sole cost
            and expense. Lessor shall utilize commercially reasonable efforts to
            have the corridor constructed by December 31, 2004. To the extent
            that Lessor does not complete the construction of the corridor by
            January 14, 2004, Lessee shall receive a day for day abatement of
            Base Rent on both the Initial Premises and the Expansion Premises
            consistent with the methodology discussed above for the division
            wall.

                                        2
<PAGE>

      9.    All other terms and conditions of the Lease shall remain in full
            force and effect. To the extent that there are any discrepancies
            between this Amendment and the original Lease, the terms of this
            Amendment shall prevail.

LESSOR:                             LESSEE:

MISSION OAKS ASSOCIATES, LLC        DECKERS OUTDOOR CORPORATION.

By:   /s/ ERI KROCH                 By: /s/ SCOTT ASH
      ---------------                   ---------------
Its:  MANAGER                       Its: CFO
Date: 1/4/05                        Date: 1/5/05

                                    By: ______________________

                                    Its: _____________________

                                    Date: ____________________

                                        3
<PAGE>

                                                                     EXHIBIT "A"

                         3001 MISSION OAKS, CAMARILLO,CA

                                  [FLOOR PLAN]

                        FOR FURTHER INFORMATION CONTACT:

SAM WAGNER X325
CHRIS LARSON X320
WILLIAM ADELMAN X349

                                                        [TOLD PARTNERS INC LOGO]
<PAGE>


                                  [FLOOR PLAN]

                                LEASE EXHIBIT B

                            MISSION OAKS ASSOC., LLC

c/o Mr. David Garcia                                       3001 MISSION OAKS BL.
Sandstone Properties, Inc.                                   CAMARILLO, CA 93012
1543 7th Street, Ste. 202
Santa Monica, CA 90401
(310)393-9000

                         [SQUARE ONE ARCHITECTURE LOGO]

                                     [SEAL]

SQUARE ONE ARCHITECTURE

3743 Valencia Ave, Simi Valley, CA 93083
805.522.6777 www.squareonearch.com
--------------------------------------
Issue date: Thursday, December 2, 2004