|[[Seiran (631 Air Group)]] (★+4)<br>[[12cm Single High-angle Gun + 25mm Machine Gun]] (★+7)<br>[[14cm Twin Gun Mount Kai 2]] (★+7)<br>[[Late Model Submarine Radar & Passive Radiolocator]] (★+4)
+
|[[Seiran (631 Air Group)]] (★+4)<br>[[12cm Single High-angle Gun Mount + 25mm Machine Guns Additions]] (★+7)<br>[[14cm Twin Gun Mount Kai 2]] (★+7)<br>[[Late Model Submarine Radar & Passive Radiolocator]] (★+4)
−
|[[Seiran (631 Air Group)]] (★+3)<br>[[12cm Single High-angle Gun + 25mm Machine Gun]] (★+4)<br>[[14cm Twin Gun Mount Kai 2]] (★+4)
+
|[[Seiran (631 Air Group)]] (★+3)<br>[[12cm Single High-angle Gun Mount + 25mm Machine Guns Additions]] (★+4)<br>[[14cm Twin Gun Mount Kai 2]] (★+4)
−
|[[Prototype Seiran]] (★+3)<br>[[12cm Single High-angle Gun + 25mm Machine Gun]] (★+2)<br>[[14cm Twin Gun Mount Kai 2]] (★+2)
+
|[[Prototype Seiran]] (★+3)<br>[[12cm Single High-angle Gun Mount + 25mm Machine Guns Additions]] (★+2)<br>[[14cm Twin Gun Mount Kai 2]] (★+2)