These Terms govern your use of the mufem software (the "Software") provided by Raiden Numerics G.K. ("we", "us"). Product-specific terms — pricing, license tiers, system requirements, and lapse behavior — are described on the mufem product page on this website and are incorporated by reference into these Terms. By installing, activating, or using the Software you agree to these Terms.

1. Purchase and billing

Subscriptions to the Software are sold through Paddle.com Market Limited, acting as Merchant of Record for the transaction. Your contract for payment, billing, invoicing, and tax collection is with Paddle; your license to use the Software is governed by these Terms. Paddle's buyer terms apply to the payment transaction: paddle.com/legal/checkout-buyer-terms.

2. License grant

We grant you a non-exclusive, non-transferable, revocable license to install and use the Software under the tier applicable to you. The free tier is granted at no charge; paid tiers are granted for the duration of your active subscription and subject to payment of the applicable fees. The tier structure is defined on the mufem product page:

• Community / free tier — free for both academic and commercial use, providing most physics models on a single workstation, with no per-seat charge.
• Individual — paid tier for a single named user, adding cluster and GPU scaling and specialized models, installable on up to 3 machines that user personally operates.

Team, site, or enterprise licenses are governed by the order form agreed with us in addition to these Terms.

3. Restrictions

You may not (a) reverse engineer, decompile, or disassemble the Software except where applicable law expressly permits, (b) remove or alter copyright or attribution notices, (c) sublicense, rent, lease, or resell the Software, (d) use the Software to develop a directly competing product, or (e) circumvent the licensing or activation mechanism.

4. Updates

We may release updates, patches, and new versions during your subscription. We are not obligated to maintain compatibility with prior versions indefinitely.

5. Termination and lapse

You may cancel your subscription at any time; the license remains valid until the end of the paid period. When a paid subscription lapses without renewal, the Software's behavior falls back to Community-tier behavior as described on the product page. Existing simulations, results, and other outputs you have produced remain yours.

We may terminate the license for material breach of these Terms, including circumvention of activation or use beyond the purchased tier.

6. Warranty disclaimer

The Software is provided "as is" without warranty of any kind, express or implied, including warranties of merchantability, fitness for a particular purpose, and non-infringement. We do not warrant that the Software will be error-free, uninterrupted, or that results will be accurate. The Software is a numerical simulation tool; its output must not be relied upon for safety-critical or life-critical decisions without independent verification by a qualified engineer. The Software is under continuous development and its APIs, defaults, and numerical results may change between versions; you should validate results after each upgrade.

7. Limitation of liability

To the maximum extent permitted by law, our aggregate liability under these Terms will not exceed the fees you paid to us in the 12 months preceding the claim. We will not be liable for indirect, incidental, consequential, special, or exemplary damages, including lost profits, lost data, or business interruption, even if advised of the possibility.

8. Export control

You agree not to use, export, re-export, or transfer the Software in violation of applicable export control and sanctions laws, including Japan's Foreign Exchange and Foreign Trade Act, the U.S. Export Administration Regulations, and the EU Dual-Use Regulation. You confirm that you are not located in, and will not provide access to the Software to any person located in, a country or to a party subject to applicable embargoes or trade restrictions.

9. Governing law

These Terms are governed by the laws of Japan, excluding conflict-of-law rules. The courts of Kyoto, Japan have exclusive jurisdiction over any dispute arising from these Terms.

10. Changes

We may update these Terms. Material changes will be communicated to active subscribers by email at least 30 days in advance. Continued use after the effective date constitutes acceptance.

11. Contact

Raiden Numerics G.K.
〒607-8131 Otsuka Minamimizo-chō 1-9, Yamashina-ku, Kyoto-shi, Kyoto, Japan
mufem@raiden-numerics.com

Effective date: June 18, 2026