In real life, Bear is a famous novelist named Ryo Sakuma. He's 47 years old and his most acclaimed work is the novel "Annwn".
He's divorced from his wife, and is constantly pestered by his son, a Wavemaster that goes by the name Teddy in The World, with demands for money.
Ryo Sakuma enjoys various hobbies, like reading books by famous authors, and going to the theatre. He smokes quite a lot, and has several dictionaries in his computer, which enable him to research anytime.
In Unison, the conversation at the bar, and certain scenes at Net Slum suggest that Bear and BT start a relationship in real life after the events in .hack//Sign