"Very close, it seems. It seems that their connection through chess led my father to stay at Mr. Ushiromiya's mansion quite often. ...Although I may not be one to talk, Mr. Ushiromiya was extremely moody. And my father was an exceedingly magnanimous man, who excelled at interacting with humans like him. It's not hard to imagine that he was a rare friend for the isolated Mr. Ushiromiya."