"Dragon Slayer - Eiyuu Densetsu (ドラゴンスレイヤー英雄伝説) is a RPG video game published by SEGA and developed by Nihon Falcom released on 1994 for the SEGA Genesis."
This statement is technically true, but there's more to this story than meets the eye.
If you look at the top right of the box art you'll see a logo that says
Sega Falcom. This was a subsidiary created by... well, you can probably guess. The point being, Sega Falcom was technically a separate entity from both Nihon Falcom and SEGA that comprised of SEGA and Falcom staff members.
So why did SEGA and Falcom come together like this in the first place?
While the SEGA Genesis sold well in North America and Europe, its Japanese equivalent (the Mega Drive) lagged behind in sales compared to the PC Engine and Super Famicom. Japan loves its RPGs, a genre with slim pickings on the Mega Drive, so SEGA thought that putting some Falcom RPGs on the system would help boost its appeal in Japan. The goal was to release a bunch of games for the SEGA CD, but sadly only one game ever released as a result of this joint venture (that game being
Popful Mail). They did however release a few games on cartridge for the Mega Drive, those being
Dragon Slayer - The Legend of Heroes,
Dragon Slayer - The Legend of Heroes II, and
Lord Monarch.
So why didn't Falcom just develop the games themselves? Why did they have to make a whole separate entity for this?
Falcom was primarily a PC developer at the time, and they rarely ever made console games. The vast majority of their games on consoles were outsourced to other companies. For example, Ys Book I & II for the PC Engine were developed by Hudson Soft (although I believe Falcom's sound team worked on the music). They also lost a lot of their creative staff around that time, meaning that they didn't have the manpower to tackle new Mega Drive projects on top of their current workload. So having a subsidiary with a mixture of Falcom and SEGA staff was necessary to get these ports made.
Falcom is one of the oldest video game companies around, and their history is incredibly fascinating. If anyone is interested in learning more about the company,
I highly recommend checking out this video by Bowl of Lentils on Youtube.