Netaji Subhash Chadra Bose, once a colleague of Gandhi, was fighting against British in non Violent way. But when World War II broke out, Bose thought that it was the best opportunity for India to get freedom by armed revolution. His plan was to co-operate with Germany and attack British India. He was sure that Indian soldiers in British army will rebel against the British Government as soon as his army will attack India. British Government house arrested him, but he escaped and went to Afghanistan, and then to Germany in April 1941. In his 2 years stay in Germany, Bose realised that  Germany is not interested in India’s independence but only to rule the world. His meeting with Hitler was one sided affair where Hitler proudly reiterated his well known ugly racist chauvinism. Bose wanted Germany to withdraw from Russia while  Hitler boasted that for Germany, it is only possible to reach India over ‘the dead body of Russia’.

Meanwhile Japan had entered the world war and had advanced towards India against British. Bose realised that collaborating with Japan at this stage will yield the desired result than with Germany. He also wanted to be nearer home when Japan decided to invade India so that he could be physically available to offer leadership to the people and the prisoners of war of Indian origin in South East Asia. Bose planed to go to Japan. Hitler arranged a submarine for Bose. It was a U-180 German submarine.

On 8th February 1943, the submarine sailed from Keil, to travel towards Indian ocean. Abid Hassan, a personal assistant and a doctor of Subhash Chandra Bose was his fellow traveler in this journey. When it detoured south Africa and turned to east, a British tanker Corbis confronted. U-180 sank the British Tanker. Three days later, a Japanese submarine I-29 met with U-180 near Madagascar. Subhash Chandra boarded on Japanese submarine which successfully and safely reached to Japan. After reaching Japan, he met Japanese Prime Minister Hideki Tojo and discussed about future strategy and plans. Later Subhash Chandra Bose attacked British India from Eastern front with Indian National Army.

Reference:

http://jainismus.hubpages.com/hub/The-Submarine-Adventure-of-Subhash-Chandra-Bose

http://www.indianage.com/show.php

http://www.revolutionarydemocracy.org/rdv7n1/Bose.htm