TOKYO, Jan 6 (Reuters) - Japan's 10-year government bond yield rose to hit the upper limit of the central bank's policy band on Friday, after the finance ministry raised the coupon rate on the notes of the same maturity auctioned in the previous session.

The yield on 10-year JGBs rose to 0.500%, its highest since July 2015 and the top of the allowance band around the benchmark yield target, which was widened to 0.5% from 0.25% last month in the central bank's surprise policy tweak.

On Thursday, Japan's Ministry of Finance raised the coupon rate on the 10-year Japanese government bonds (JGBs) to 0.5% from the previous 0.2%, the highest level since December 2014.

Yields on other tenors fell as the Bank of Japan (BOJ) conducted emergency bond buying operations for notes maturing five to 10 years, in addition to its scheduled operations for notes maturing between one to 25 years.

The BOJ later announced to hold a two-year pooled collateral operation for a third straight session, supplying financial institutions with cash amounting to 2 trillion yen ($14.91 billion) at a 0% interest, a move aimed at encouraging investors to buy 2-year government notes.

The two-year JGB yield, which turned positive for the first time in 7 years last month, fell 0.5 basis point to 0.010%.

"The BOJ said it widened the band for 10-year yield in order to restore market functions, but looking at the series of operations, its motive could have been something else," said Masayuki Koguchi, general manager - fixed income investment division, Mitsubishi UFJ Kokusai Asset Management.

The 20-year JGB yield, which hit the eight-year high of 1.350% this week, fell 1.5 basis points (bps).

The 30-year JGB yield fell 1.5 bps to 1.600%. The 40-year JGB yield also fell 1.5 bps to 1.870%.

The five-year yield fell 1 bp to 0.195%.

Benchmark 10-year JGB futures rose 0.22 yen to 145.88, with a trading volume of 12,293 lots. ($1 = 134.1400 yen) (Reporting by Junko Fujita; Editing by Rashmi Aich)