Hokuto Corporation (DMM.com) is NOT a AV production company (it does not make JAV).
It is a distribution company. It distributes the DVDs to stores all over Japan (and online via DMM.com).
AV production companies (e.g. S1, Moodyz, IdeaPocket, PREMIUM, etc.) make the DVDs.
Production companies have a business agreement with Hokuto to distribute the DVDs they make.
AV stars (eg. Yuma, Sora, RIO, etc.) have a contract with a production company (who have an agreement with Hokuto).
Indirectly, the JAV actresses work for Hokuto Corp.
Ebimasu was made by TV Tokyo. The program was sponsored by DMM.com.
DMM.com paid money to TV Tokyo to make Ebimasu.
I did some research about how much it costs to make a program like Ebimasu.
In the US, 30 minutes of TV costs between $350,000 to $500,000 to make.
Probably, Ebimasu cost a lot less than that...say, $150,000 per episode.
That's $600,000 per month! DMM spent that money because Ebimasu helped them sell more DVDs.
In 2008 (when Ebimasu started), Hokuto's business was very good.
By 2013, Hokuto wasn't doing so good, and Ebimasu's big names were retiring or heading towards retirement.
Ebimasu - TV Tokyo - DMM.com decided to end the program for business reasons.