"No matter how much the yen weakens from the current level we are unlikely to see a sharp recovery in exports, " said Junko Nishioka, chief economist at RBS Securities in Japan.

BBC: Japan posts trade deficit for eighth straight month

"The market had concerns about the BOJ announcing any policy actions today, but the BOJ's decisions exceeded investor expectations, " said Junko Nishioka, Chief Economist at RBS Securities Japan, in a note.

WSJ: Nikkei Rebounds on BOJ Outcome

"Kuroda made good on his promise of boosting monetary easing in terms of both volume and types of assets that the bank purchases, " said Junko Nishioka, chief Japan economist at RBS Securities in Tokyo.

BBC: Haruhiko Kuroda