so did sega japan ignore their part in sinking the s.s. sega?
Going by what the Segagaga Blog said on the subject, Segagaga viewed themselves as the "wunderkind" (in the blog's words) who were a font of creativity and joy that were squelched by the "shrewd" Americans looking to turn a profit
This is in reference to real-life turmoil between Sega Japan and Sega of America - in order to get their foot in the door in America, Sega of Japan appointed Tom Kalinske as head of Sega of America. Japan thought a lot of his proposed methods were insane - Kalinske was responsible for deciding to pack Sonic the Hedgehog in with the Genesis, for instance, which Japan hated because they didn't want to give away their best game for free.
Kalinske was a smart man, and made Mattel a force to be reckoned with before going to Sega. His methods took Sega from less than 1% market share to an even 50% split with Nintendo. Officially, he made Sega of America more profitable and more successful than Sega of Japan.
Sega of Japan
hated that. They did not view Sega of America or Tom Kalinske as "equals". In their eyes, Kalinske's success was making a mockery of Japan's domestic struggles to make the Mega Drive relevant. The hired help turned out to be smarter and better than their masters. So, they did what seemed natural to them: they punished Kalinske for being too successful.
He got tired of being stonewalled and left the company.
It's not hard to imagine that Sega of Japan thought that they were precious artists being spoiled by Sega of America's big business. The parallels between Segagaga's "Special Task Force Director Cool" from America and Tom Kalinske are apparently pretty obvious. According to the Segagaga Translation blog, Director Cool is responsible for almost destroying the company with his shrewd business sense, which is obviously not what was actually happening with the real Sega.
Pay attention to the company's history and you learn that Sega of Japan seems to be its own worst enemy.