|“||Yes! I really love and respect him! Onii chan is my idol!||”|
In a 2007 episode Sunetsugu was shown to be arrogant towards Nobita, much like Suneo. His personality was changed to a more well-mannered and naive person in later episodes.
Sunetsugu has a great respect for his older brother, but only because of Suneo's arrogant brags and lies in their correspondence. He appears to be very naive and innocent to believe all those lies so easily. He is also the opposite of Suneo in many ways: he is well mannered and doesn't boast or talk much at all, and is not as arrogant as Suneo. He seems to take after is father, who isn't shown to be a boastful or arrogant person. Suneo, on the other hand, takes after his mother.
- In the 2005 anime episode Arigataya, Sunetsugu was shown with brown hair and smaller eyes, and did not resemble Suneo as much. He was remodeled for later episodes and currently strongly resembles his family members.
- In the Tagalog version, his name is changed into Sunegu.
- His name is changed to Xưki in Vietnamese.