Renhai Reflections 61: Shifting
"The main feature of all Japanese linked poetry is shifting: Shifting from place to place, action to action, mood to mood. There is no sustained narrative or setting as in most long poems of European tradition." (The Haiku Seasons by William J. Higginson, p. 46)
Renhai is based on principles of Japanese linked poetry including the shifting that William Higginson here speaks of. The concept of "theme" in Renhai, however, is intended to pull together a Renhai's verses and to create something that is more than a collection of three linked verses.