TOKYO - The Bank of Japan will raise its key interest rate this month and again in the fourth quarter, taking borrowing costs to 1.25% by year-end, as it grows more wary of inflation risks than downside hazards to the economy, a Reuters poll of economists showed. BOJ Governor Kazuo Ueda all but cemented a June rate hike in a speech last week, marking a clear shift in the central bank's narrative toward fighting inflation and opening the door to more frequent increases in borrowing costs.