Dr Ryuta Kawashima, known to millions as him what did the Brain Training for DS, has revealed he hasn't made a single yen off the profits.
That's not because Nintendo's being mean, though - it's all his own choice.
As reported by AFP, 17 million Brain Training games have been sold around the globe, netting royalties of JPY 2.4 billion (GBP 11 million). Under the terms of his employment contract with Tohoku University, Kawashima could take up to half the proceeds while the rest would go to his college. But the good doctor said his annual salary of JPY 11 million (GBP 50,000) is plenty enough to live on.
"Not a single yen has gone in my pocket. Everyone in my family is mad at me but I tell them that if they want money, go out and earn it," he revealed.
Kawashima doesn't play Brain Training himself these days, reckoning the research work he does keeps his mind in shape. As for his body - "If there is time for physical exercise, I want to use it for research." So when he wanted to lose 20kg last year, Kawashima just stopped eating so many pies.
He's not too keen on his sons spending hours playing games either. They're banned from going near the things on weekdays, and only get one hour at weekends. Kawashima once destroyed a game disc when they broke the rules.
"What is scary about games is that you can kill as many hours as you want," he said. "I don't think playing games is bad in itself but it makes children unable to do what they should do such as study and communication with the family."
Apparently Kawashima has been fascinated by brains since he was a teenager. While most of us were listening to bad music and discovering self-love, he was thinking how to put "my brain in a computer so it would be around to see the last day of humanity".
These days Kawashima is working with Toyota to design a car that will help elderly people stay alert and avoid accidents. Better hurry up: "I'm confident I'll go senile. Researchers, especially those in medical fields, are said to die of what they are studying. Since I've been studying the brain, I'll die of a brain disease." Little hope for those of us likely to die of Wii mini-games then.