Amagasaki Line (Amagasaki Kisen-bu) "<i>Akagi Maru</i>", Successor of the <a href="https://en.wikipedia.org/wiki/Japanese_gunboat_Akagi" class="extiw" title="en:Japanese gunboat Akagi">Japanese gunboat "<i>Akagi </i>"</a>.
Unknown (Amagasaki Line)
"Illustrated history talk fleet flag of the Rising Sun" by Goro Yamataka