* '''2022-04-01:''' Became upgradable from {{Equipment/Link|10cm Twin High-angle Gun Mount}}
* '''2022-04-01:''' Became upgradable from {{Equipment/Link|10cm Twin High-angle Gun Mount}}
* '''2024-04-30:''' Visible bonuses added when improved (for Akizuki-class)
* '''2024-04-30:''' Visible bonuses added when improved (for Akizuki-class)
−
* '''2024-06-27:''' Became upgradeable to {{Equipment/Link|10cm Twin High-angle Gun Mount Kai + Anti-Aircraft Fire Director Kai}}
+
* '''2024-06-27:''' Became upgradeable to {{Equipment/Link|10cm Twin High-angle Gun Mount Kai + Anti-Aircraft Fire Director Kai}}, name used in the comparison menu, library and CG changed to "10cm Twin High-angle Gun Mount + Anti-Aircraft Fire Director" (10cm連装高角砲+高射装置)