The BOJ and BOE managed the medium term price stability 15+1 % as permitted by the monetary policy on GBPJPY. After reaching upper medium term band, the GBPJPY sterilized by the two central banks to bring the pair down to central band/central parity at 136.00/137.00. At such, GBPJPY will break the lower monthly band 139.00/139.50 down to her central band/central parity in short-term.
im also short on this pair
best of luck