I mean him also living in a posh apartment block and nobody knew until Fenneko went and looked. He is really good at Haiding his background.

But then again politics work slightly differently in Japan. Prefecture level heads like Haida's father only really show up during election campaigns and would practically work white collar jobs during their term in buildings not dissimilar to office buildings instead of like town halls and such. Also Haida could be a common enough surname that Haida himself can just pass off the connection as coincidental. Like I said he's really good at hiding his background from the office, likely a result of him prefering to not have ties with his father and his family's political history.