The 'Mitsubishi' G4M1 "Betty" marked 'Z-739' as unit of 1st Kokutai belonging in 21st Koku Sentai, Naval Air Service, detached in Tainan, South Taiwan, December 1941. your unit,the 1st Kokutai was equiped with 48 planes and your near group Kanoya Kokutai if conformed with 72 aircraft based in Kaohsiung and Tainan bases with Command in last airfield.these groups colaborated with Toko Kokutai, at same time equiped with 24 Kawanishi H6K4 "Mavis" Heavy Bomber Flying Boats, based in Toko naval base.… (More on Z-739)