After her second modification, Isuzu became the AA boss. In reality, without participating in anti submarine operations, Isuzu joined the Leyte Campaign together as part of the destroyer squadron and took part in anti air defence.Built in the Taishou era, Isuzu is already an old lady when the war starts, so she received various improvements. But because of the worsening situations, the other Nagara class girls never received these modifications.When talking about Isuzu, of course it's about modifications.
First modification that gave her the precious radar, and
Second modification that gave her that fabulous boobs and anti-air capability.And in the end, of all thing she's sunk by the subs.
Isuzu-chan can't win against submarines.