'U' (i) was the Japanese maritime undertaking to deliver Lieutenant General Renya Mutaguchi’s 18^th Division and Lieutenant General Masao Watanabe’s 56^th Division, together with a number of other units to newly captured Rangoon, the capital of Burma (25 March/14 April 1942).

For this undertaking, the Imperial Japanese navy’s Transport Unit No. 3 departed Singapore with 32 ships including the 9,492-ton Teikai Maru, 9,256-ton Anyo Maru, 5,829-ton England Maru, 8,613-ton Ginyo Maru, 5,724-ton Kuwayama Maru, 2,910-ton Kochi Maru, 3,377-ton Kenkoku Maru, 4,013-ton Samarang Maru, 4,645-ton Suez Maru, 2,478-ton Taikai Maru, 5,477-ton Tazan Maru, 5,271-ton Hamburg Maru, 6,446-ton Buyo Maru, 5,652-ton Havre Maru, 5,858-ton Brazil Maru, 5,214-ton Penang Maru, 8,359-ton Hokuriku Maru, 6,570-ton Montreal Maru, 1,852-ton Yawata Maru and 5,274-ton Yoneyama Maru.

While the main strength of the two divisions travelled from Singapore, some other of their elements made their passage to Rangoon in multi-ship convoys from Japan and Penang in western Malaya. The latter convoy included the 6,359-ton transport Aobasan Maru, was supported on its passage from Malaya by the escort vessel Shimushu, and was preceded into Rangoon harbour by the minesweepers W-1 and W-4. Another convoy delivered further reinforcement in the form of the 1^st Tank Regiment, 14^th Tank Regiment, two regiments of heavy field artillery, two independent engineer regiments and a number of supporting anti-tank, anti-aircraft, signals and line of communication units.

After being delivered to Rangoon, the divisions and units moved to join the 'B' (iii) operation of Lieutenant General Shojiro Iida’s 15^th Army (Lieutenant General Shozo Sakurai’s 33^rd Division and Lieutenant General Hiroshi Takeuchi’s 55^th Division) to take central and northern Burma from the British, who by this time had considerable Chinese support.