You can find a reference to all my Japanese ship camouflage posts at:
https//wetherhorn.wordpress.com/2022/07/12/japanese-ship-camouflage-cross-reference/
The Japanese Imperial Army had a ministry of its own. There was also an independent authority for handling merchant vessels that had not been requisitioned by either service. The two authorities, Army and Navy, were supposed to be equal, but they did not always agree about everything. One point of disagreement was ship camouflage. The Army requisitioned many merchant vessels to carry invasion forces and supplies. Those ships were often given camouflage patterns, especially during the early part of the war when the Navy was still using uniform solid overall grey colors. Later in the war there was a change, and even aircraft carrier decks were given camouflage, Those two items have been covered in later posts. Meanwhile, here are some pictures of and patterns for Army ships in early war camouflage:
Wetherhorn 