Identify the key social groups portrayed in "Obasan."
The social groups portrayed in this novel are on sliding scales from ethno-centric to accepting. On one side is Grandma Kato and Old Man Gower; on the other side, Naomi and Bill. Racism and fear are what slide along this scale.
Old Man Gower's group is the old-fashioned and long-established Canadian citizenry. He represents the arrogance of a social group who believes that they are in control of a land and society because they have been there longer. He looks upon the Japenese immigrants as less than himself, as demonstrated most hideously in his sexual abuse of Naomi.
Grandma Kato represents the alienated immigrant population. Unable to adjust to a lifestyle foreign and unwelcoming to her, Kato never assimilates into life in Canada. She is constantly looking back towards the country she left - and for Grandma, she literally goes back to Japan, causing the separation in the family at the outset of WWII.
Naomi represents the integrated immigrant. Although she suffered at the hands of her government during the war, the present-day Naomi has grown up and accepted her "new" country. She lives and works successfully in Canadian culture as an adult.
"Rough Lock" Bill - like Naomi - represents the more balanced view of his own culture. He does not see the world as separated by races and nationalities. He sees peoples as individuals, as demonstrated by his rescue of Naomi from drowning. While his country were trying to lock up anyone with Naomi's background, he was risking his own neck to save her.