Amagi and her sistership Akagi were battlecruisers of the Japanese 8-8 programme building at the end of WW1. Japan agreed to cancel the programme at the Washington Treaty in 1922 and conversion to aircraft carriers commenced. Amagi's hull was badly damaged in the Tokyo earthquake and so she was scrapped. Akagi went on to serve in WW2. Of the two models available, one is labelled underneath Amagi and one is Akagi.
The curved fore-funnel is conjectural but follows the pattern of alterations to Nagato & Mutsu in the 1920s.