Japan's Finance Minister Satsuki Katayama said the principles behind the coordinated Japan-US currency intervention in July remain in place, indicating Tokyo could pursue joint action with Washington again if needed. The yen weakened beyond 158 per dollar after the Bank of Japan's rate hike on Friday lifted borrowing costs to a 31-year high but failed to convince investors that more aggressive tightening was imminent. Japanese authorities also conducted rate checks in overseas markets, a step often viewed as a precursor to currency intervention. The yen strengthened briefly afterward, but those gains quickly faded. Katayama declined to comment on specific foreign-exchange levels.