<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2022-09-15</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001916608</issuerCik>
        <issuerName>TCW Star Direct Lending LLC</issuerName>
        <issuerTradingSymbol>NONE</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001948122</rptOwnerCik>
            <rptOwnerName>NLGI US Private Debt Fund II</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O MUFG FUND SERVICES (CAYMAN) LIMITED</rptOwnerStreet1>
            <rptOwnerStreet2>MUFG HOUSE, 227 ELGIN AVE P.O. BOX 609</rptOwnerStreet2>
            <rptOwnerCity>GRAND CAYMAN</rptOwnerCity>
            <rptOwnerState></rptOwnerState>
            <rptOwnerZipCode>KY1-1107</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000905591</rptOwnerCik>
            <rptOwnerName>NIPPON LIFE INSURANCE CO</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1-6-6 MARUNOUCHI</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>TOKYO</rptOwnerCity>
            <rptOwnerState>M0</rptOwnerState>
            <rptOwnerZipCode>100-8288</rptOwnerZipCode>
            <rptOwnerStateDescription>JAPAN</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Limited Liability Company Units</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3753190</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">This report is filed jointly by NLGI US Private Debt Fund II, a Cayman Islands Unit Trust (the &quot;Fund&quot;), and Nippon Life Insurance Company, a Japanese mutual life insurance company (&quot;Nippon&quot;). The Fund is the direct owner of 3,753,190 Common Units of the Issuer. Nippon holds a majority of the equity interests in the Fund.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>NIPPON LIFE INSURANCE COMPANY, /s/ Hironao Kunita</signatureName>
        <signatureDate>2022-09-23</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>NLGI US PRIVATE DEBT FUND II, By: MUFG FUND SERVICES (CAYMAN) LIMITED acting solely in its capacity as trustee of the NLGI US Private Debt Fund II, /s/ Anneka Bavalia, /s/ Carla Drysdale</signatureName>
        <signatureDate>2022-09-23</signatureDate>
    </ownerSignature>
</ownershipDocument>
