Just for the record, Dr. Campbell (Link), the Nippon Professional Baseball league's record for most home runs in a season has been held by a foreigner since 1964* -- O Sadaharu being a citizen of the Republic of China.
O's retentions of the citizenship of a lost state -- his father hails not from Taiwan but from Zhejiang -- was the reason he could not play at the Kokutai (the national sports festival takes its once-in-a-half-century's turn in Tokyo starting on September 28 - Link - J) despite being a hero at Koshien.
The sublimation of O's citizenship -- what, the first person awarded a Kokumin Eiyosho is not a kokumin? -- and later players' dutiful protection of the record makes for an interesting study of the notion of ethnicity, loyalty and gradations within insider/outsider divisions.
* Why has no one seen it fit an interview Nomura Katsuya, the Japanese player O took the record from? If there is anyone in this blessed land with an otherwise unspeakable opinion and willingness to express it, it's Nomura.