You didn't see this, did you?

https://www.facebook.com/story.php?story_fbid=2546543432029704&id=100064693388551

Because if you did, you've stumbled into a world of confusion and misinformation.

The model shown is by Lindberg, and is an unfortunate product of inaccurate research. The b&w photo shown in this link of a real sub is of "the original" I-53. In 1942, the IJN renumbered their sub fleet, and that sub got renumbered I-153. A new I-53 was built. That was a completely different animal...this second I-53 was a Type C sub.

The old sub, now I-153, was built well before the war, and was relegated to rear area service during the war. Mostly training duty.

The new Type C I-53 was the one which became a kaiten carrier.

The folks at Lindberg failed to sort this out, and their model has features from both subs, making a fine mess.

The old sub, of the b&w photo, has no AA guns because when she was built, they were not considered necessary. The new I-53 had AA guns. Some might have been removed for the kaitens, but she should have retained her conning tower pair.

Here's a model of sister sub I-52, before conversion to any sort of carrier. Note the AA guns:

https://sdmodelmakers.com/type-c-mod-i52-class-japanese-submarine-model-14-inch.html

Here is info on both the subs I have discussed:

The original I-53 turned I-153:

http://www.combinedfleet.com/I-153.htm

The 1942 I-53 Kaiten carrier:

http://www.combinedfleet.com/I-53.htm