Ehime Prefecture is best known for hot springs, citrus fruit and cycling. It is also home to some savvy bond traders.

Iyogin Holdings, a regional bank based in the prefectural capital of Matsuyama, has delivered record net income for two years in a row, driven by returns on its investments in Treasurys and other foreign bonds.

That makes the bank the only one of the country¡¯s 73 regional lenders to book gains from bonds over that time period, according to SMBC Nikko Securities. It also stands in contrast to the country¡¯s premier agricultural bank, Norinchukin, which expects a loss of at least ?500 billion ($3.2 billion) this fiscal year because of losses on foreign notes.