Having found a note that accompanied the scroll with the tennyo, the tengu and the fisherman, I relist it here in "translations".
Being rather short I fear it does not clear up the story behind it.
Right - no story in that. It just says "I put my heart and soul into this drawing, so I would be grateful if you enjoyed it and kept it in your collection for a long time", from the artist, Yoshida Hidemitsu.