For a monthly fee, DoCoMo customers can use Napster Mobile to access full-length songs and ringtones that can be delivered over-the-air (OTA), directly to their mobile handset for listening and downloading.

The launch of Napster Mobile’s OTA music delivery service on iMode marks an expansion of the relationship between Napster and DoCoMo. The companies’ relationship officially kicked-off last month when Napster and Tower Records Japan launched Napster Japan, the country’s first PC-based music subscription service, which offers compatibility with a variety of current and future DoCoMo mobile handsets.

Using a compatible DoCoMo handset lets Napster Japan’s Napster To Go portable subscription customers transfer their music from their PC directly to their mobile phone.

iMode customers can subscribe to Napster Mobile for unlimited access to Napster Mobile’s music programming features, including personalized recommendations, featured artists and new releases and to browse Napster Mobile’s catalog of full-length songs and ringtones.

Napster Mobile subscribers in Japan pay a monthly access fee of approximately $3 per month, and can acquire individual songs and ringtones for mobile delivery and download using a credit-based system. Subscribers receive 300 credits per month to procure individual songs and ringtones, and they can purchase additional credits at any time.

Full-length songs from Napster Mobile can be delivered over-the-air and downloaded to a variety of different DoCoMo handsets, including the N902iX, the SH903i, the F903i, the D903i and other soon to be released models in the 903i series.