In September–October 1940, the ship was based at Hainan Island to support the Japanese invasion of French Indochina. In February 1941, Sōryū moved to Taiwan to reinforce the blockade of southern China.Hata, Izawa & Shores, p. 151 Two months later, the 2nd Carrier Division was assigned to the First Air Fleet, or Kido Butai, on 10 April.Tully Sōryūs air group was detached in mid-July and transferred to Hainan Island to support the occupation of southern Indochina. Sōryū returned to Japan on 7 August and became flagship of the 2nd Division. She was relieved of that role on 22 September as she began a short refit that was completed on 24 October. The ship arrived at Kagoshima two days later and she resumed her former role as flagship of the Division.
In September–October 1940 the ship was based at Hainan Island to support the Japanese invasion of French Indochina In February 1941 Sōryū moved to Taiwan to reinforce the blockade of southern ChinaHata Izawa & Shores p 151 Two months later the 2nd Carrier Division was assigned to the First Air Fleet or Kido Butai on 10 AprilTully Sōryūs air group was detached in mid-July and transferred to Hainan Island to support the occupation of southern Indochina Sōryū returned to Japan on 7 August and became flagship of the 2nd Division She was relieved of that role on 22 September as she began a short refit that was completed on 24 October The ship arrived at Kagoshima two days later and she resumed her former role as flagship of the Division