Sega Game Toshokan (known in-game as the Sega Game Library) was a digital game distribution service developed by Sega for the Sega Mega Drive in Japan. It was later discontinued on March 1993.
Released alongside the Mega Modem accessory (and was optionally bundled with it), the software allowed its subscribers (who subscribed to the 800円 monthly fee) to use the peripheral to download small-sized games to the cartridge for play. In addition, it features an online newsletter (Sega Net News) and downloadable game soundtracks (Sega Music Collection).
This concept would later be revisited outside of Japan with the Sega Channel cartridge-based modem peripheral.
Most of these games were later included in some compilations and official emulation services, most notably the Game no Kanzume compilation series.