|“||I'm Sewashi Nobi, your great-great-grandson!||”|
— Sewashi Nobi to Nobita Nobi, All the Way From the Country of the Future
In the 1973 anime, he wore a red and white jumpsuit. He also wore glasses like Nobita, but they were removed in the subsequent anime series. In the 1979 anime, he wore a teal and white shirt, white long pants with a red belt as well as teal boots. He wears a jumpsuit with a turtleneck shirt underneath in the 2005 anime and Stand by Me Doraemon, although the color schemes are different.
Sewashi, like his ancestors, does not perform well in school, but is otherwise quite athletic.
Not much is know about Sewashi's family than his great-great-grandparents, Nobita and Shizuka.
Sewashi's mother is only shown once, and resembles Nobita's mother, but more futuristic, a bit nicer and wears no glasses. Sewashi's father, who is Nobita and Shizuka's great-grandson, has appeared in the series a few times (in the short movie, 2112: The Birth of Doraemon).
It is known that Nobisuke (Shizuka and Nobita's son) is his great-grandfather and that Nobita's parents are his great-great-great-grandparents.
- In the 1973 anime, Sewashi wears glasses and red clothes (which he almost looked like Nobita), which was changed in the 1979 and 2005 anime.
- In the official English manga and anime, Sewashi Nobi is renamed to Soby Nobi.
- In the 2014 movie, Stand by Me Doraemon, his hair color is changed to ginger and his clothes are re-colored.
- Fans often speculated that Sewashi had fabricated the photo album that he shown to Nobita in the first chapter, as in Doraemon's prediction the photo of Nobita in full body cast was unchanged when the timeline was altered.
- Given that Doraemon's model was mass-produced, however, many would have access to similar pieces of technology. It can be presumed that changing the past is generally considered risky - Sewashi is so far the only character that is known for doing so,
- Sewashi comes from the 22nd Century in the 1979 and 2005 Anime. But, he came from the 21st century in the 1973 Anime which suggested that he is Nobita's son or Nobita's grandson or Nobita's great grandson